Stay ahead of learning milestones! Enroll in a class over the summer!

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k a April Highlights and 2025 AoPS Online Class Information
jlacosta   0
Apr 2, 2025
Spring is in full swing and summer is right around the corner, what are your plans? At AoPS Online our schedule has new classes starting now through July, so be sure to keep your skills sharp and be prepared for the Fall school year! Check out the schedule of upcoming classes below.

WOOT early bird pricing is in effect, don’t miss out! If you took MathWOOT Level 2 last year, no worries, it is all new problems this year! Our Worldwide Online Olympiad Training program is for high school level competitors. AoPS designed these courses to help our top students get the deep focus they need to succeed in their specific competition goals. Check out the details at this link for all our WOOT programs in math, computer science, chemistry, and physics.

Looking for summer camps in math and language arts? Be sure to check out the video-based summer camps offered at the Virtual Campus that are 2- to 4-weeks in duration. There are middle and high school competition math camps as well as Math Beasts camps that review key topics coupled with fun explorations covering areas such as graph theory (Math Beasts Camp 6), cryptography (Math Beasts Camp 7-8), and topology (Math Beasts Camp 8-9)!

Be sure to mark your calendars for the following events:
[list][*]April 3rd (Webinar), 4pm PT/7:00pm ET, Learning with AoPS: Perspectives from a Parent, Math Camp Instructor, and University Professor
[*]April 8th (Math Jam), 4:30pm PT/7:30pm ET, 2025 MATHCOUNTS State Discussion
April 9th (Webinar), 4:00pm PT/7:00pm ET, Learn about Video-based Summer Camps at the Virtual Campus
[*]April 10th (Math Jam), 4:30pm PT/7:30pm ET, 2025 MathILy and MathILy-Er Math Jam: Multibackwards Numbers
[*]April 22nd (Webinar), 4:00pm PT/7:00pm ET, Competitive Programming at AoPS (USACO).[/list]
Our full course list for upcoming classes is below:
All classes run 7:30pm-8:45pm ET/4:30pm - 5:45pm PT unless otherwise noted.

Introductory: Grades 5-10

Prealgebra 1 Self-Paced

Prealgebra 1
Sunday, Apr 13 - Aug 10
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Prealgebra 2 Self-Paced

Prealgebra 2
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Introduction to Algebra A Self-Paced

Introduction to Algebra A
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Introduction to Counting & Probability Self-Paced

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Introduction to Algebra B Self-Paced

Introduction to Algebra B
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Introduction to Geometry
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Intermediate: Grades 8-12

Intermediate Algebra
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Precalculus
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Advanced: Grades 9-12

Olympiad Geometry
Tuesday, Jun 10 - Aug 26

Calculus
Tuesday, May 27 - Nov 11
Wednesday, Jun 25 - Dec 17

Group Theory
Thursday, Jun 12 - Sep 11

Contest Preparation: Grades 6-12

MATHCOUNTS/AMC 8 Basics
Wednesday, Apr 16 - Jul 2
Friday, May 23 - Aug 15
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Tues & Thurs, Jul 8 - Aug 14 (meets twice a week!)

MATHCOUNTS/AMC 8 Advanced
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F=ma Problem Series
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WOOT Programs
Visit the pages linked for full schedule details for each of these programs!


MathWOOT Level 1
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ChemWOOT
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Programming

Introduction to Programming with Python
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USACO Bronze Problem Series
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Physics

Introduction to Physics
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Physics 1: Mechanics
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Relativity
Sat & Sun, Apr 26 - Apr 27 (4:00 - 7:00 pm ET/1:00 - 4:00pm PT)
Mon, Tue, Wed & Thurs, Jun 23 - Jun 26 (meets every day of the week!)
0 replies
jlacosta
Apr 2, 2025
0 replies
k i Peer-to-Peer Programs Forum
jwelsh   157
N Dec 11, 2023 by cw357
Many of our AoPS Community members share their knowledge with their peers in a variety of ways, ranging from creating mock contests to creating real contests to writing handouts to hosting sessions as part of our partnership with schoolhouse.world.

To facilitate students in these efforts, we have created a new Peer-to-Peer Programs forum. With the creation of this forum, we are starting a new process for those of you who want to advertise your efforts. These advertisements and ensuing discussions have been cluttering up some of the forums that were meant for other purposes, so we’re gathering these topics in one place. This also allows students to find new peer-to-peer learning opportunities without having to poke around all the other forums.

To announce your program, or to invite others to work with you on it, here’s what to do:

1) Post a new topic in the Peer-to-Peer Programs forum. This will be the discussion thread for your program.

2) Post a single brief post in this thread that links the discussion thread of your program in the Peer-to-Peer Programs forum.

Please note that we’ll move or delete any future advertisement posts that are outside the Peer-to-Peer Programs forum, as well as any posts in this topic that are not brief announcements of new opportunities. In particular, this topic should not be used to discuss specific programs; those discussions should occur in topics in the Peer-to-Peer Programs forum.

Your post in this thread should have what you're sharing (class, session, tutoring, handout, math or coding game/other program) and a link to the thread in the Peer-to-Peer Programs forum, which should have more information (like where to find what you're sharing).
157 replies
jwelsh
Mar 15, 2021
cw357
Dec 11, 2023
k i C&P posting recs by mods
v_Enhance   0
Jun 12, 2020
The purpose of this post is to lay out a few suggestions about what kind of posts work well for the C&P forum. Except in a few cases these are mostly meant to be "suggestions based on historical trends" rather than firm hard rules; we may eventually replace this with an actual list of firm rules but that requires admin approval :) That said, if you post something in the "discouraged" category, you should not be totally surprised if it gets locked; they are discouraged exactly because past experience shows they tend to go badly.
-----------------------------
1. Program discussion: Allowed
If you have questions about specific camps or programs (e.g. which classes are good at X camp?), these questions fit well here. Many camps/programs have specific sub-forums too but we understand a lot of them are not active.
-----------------------------
2. Results discussion: Allowed
You can make threads about e.g. how you did on contests (including AMC), though on AMC day when there is a lot of discussion. Moderators and administrators may do a lot of thread-merging / forum-wrangling to keep things in one place.
-----------------------------
3. Reposting solutions or questions to past AMC/AIME/USAMO problems: Allowed
This forum contains a post for nearly every problem from AMC8, AMC10, AMC12, AIME, USAJMO, USAMO (and these links give you an index of all these posts). It is always permitted to post a full solution to any problem in its own thread (linked above), regardless of how old the problem is, and even if this solution is similar to one that has already been posted. We encourage this type of posting because it is helpful for the user to explain their solution in full to an audience, and for future users who want to see multiple approaches to a problem or even just the frequency distribution of common approaches. We do ask for some explanation; if you just post "the answer is (B); ez" then you are not adding anything useful.

You are also encouraged to post questions about a specific problem in the specific thread for that problem, or about previous user's solutions. It's almost always better to use the existing thread than to start a new one, to keep all the discussion in one place easily searchable for future visitors.
-----------------------------
4. Advice posts: Allowed, but read below first
You can use this forum to ask for advice about how to prepare for math competitions in general. But you should be aware that this question has been asked many many times. Before making a post, you are encouraged to look at the following:
[list]
[*] Stop looking for the right training: A generic post about advice that keeps getting stickied :)
[*] There is an enormous list of links on the Wiki of books / problems / etc for all levels.
[/list]
When you do post, we really encourage you to be as specific as possible in your question. Tell us about your background, what you've tried already, etc.

Actually, the absolute best way to get a helpful response is to take a few examples of problems that you tried to solve but couldn't, and explain what you tried on them / why you couldn't solve them. Here is a great example of a specific question.
-----------------------------
5. Publicity: use P2P forum instead
See https://artofproblemsolving.com/community/c5h2489297_peertopeer_programs_forum.
Some exceptions have been allowed in the past, but these require approval from administrators. (I am not totally sure what the criteria is. I am not an administrator.)
-----------------------------
6. Mock contests: use Mock Contests forum instead
Mock contests should be posted in the dedicated forum instead:
https://artofproblemsolving.com/community/c594864_aops_mock_contests
-----------------------------
7. AMC procedural questions: suggest to contact the AMC HQ instead
If you have a question like "how do I submit a change of venue form for the AIME" or "why is my name not on the qualifiers list even though I have a 300 index", you would be better off calling or emailing the AMC program to ask, they are the ones who can help you :)
-----------------------------
8. Discussion of random math problems: suggest to use MSM/HSM/HSO instead
If you are discussing a specific math problem that isn't from the AMC/AIME/USAMO, it's better to post these in Middle School Math, High School Math, High School Olympiads instead.
-----------------------------
9. Politics: suggest to use Round Table instead
There are important conversations to be had about things like gender diversity in math contests, etc., for sure. However, from experience we think that C&P is historically not a good place to have these conversations, as they go off the rails very quickly. We encourage you to use the Round Table instead, where it is much more clear that all posts need to be serious.
-----------------------------
10. MAA complaints: discouraged
We don't want to pretend that the MAA is perfect or that we agree with everything they do. However, we chose to discourage this sort of behavior because in practice most of the comments we see are not useful and some are frankly offensive.
[list] [*] If you just want to blow off steam, do it on your blog instead.
[*] When you have criticism, it should be reasoned, well-thought and constructive. What we mean by this is, for example, when the AOIME was announced, there was great outrage about potential cheating. Well, do you really think that this is something the organizers didn't think about too? Simply posting that "people will cheat and steal my USAMOO qualification, the MAA are idiots!" is not helpful as it is not bringing any new information to the table.
[*] Even if you do have reasoned, well-thought, constructive criticism, we think it is actually better to email it the MAA instead, rather than post it here. Experience shows that even polite, well-meaning suggestions posted in C&P are often derailed by less mature users who insist on complaining about everything.
[/list]
-----------------------------
11. Memes and joke posts: discouraged
It's fine to make jokes or lighthearted posts every so often. But it should be done with discretion. Ideally, jokes should be done within a longer post that has other content. For example, in my response to one user's question about olympiad combinatorics, I used a silly picture of Sogiita Gunha, but it was done within a context of a much longer post where it was meant to actually make a point.

On the other hand, there are many threads which consist largely of posts whose only content is an attached meme with the word "MAA" in it. When done in excess like this, the jokes reflect poorly on the community, so we explicitly discourage them.
-----------------------------
12. Questions that no one can answer: discouraged
Examples of this: "will MIT ask for AOIME scores?", "what will the AIME 2021 cutoffs be (asked in 2020)", etc. Basically, if you ask a question on this forum, it's better if the question is something that a user can plausibly answer :)
-----------------------------
13. Blind speculation: discouraged
Along these lines, if you do see a question that you don't have an answer to, we discourage "blindly guessing" as it leads to spreading of baseless rumors. For example, if you see some user posting "why are there fewer qualifiers than usual this year?", you should not reply "the MAA must have been worried about online cheating so they took fewer people!!". Was sich überhaupt sagen lässt, lässt sich klar sagen; und wovon man nicht reden kann, darüber muss man schweigen.
-----------------------------
14. Discussion of cheating: strongly discouraged
If you have evidence or reasonable suspicion of cheating, please report this to your Competition Manager or to the AMC HQ; these forums cannot help you.
Otherwise, please avoid public discussion of cheating. That is: no discussion of methods of cheating, no speculation about how cheating affects cutoffs, and so on --- it is not helpful to anyone, and it creates a sour atmosphere. A longer explanation is given in Seriously, please stop discussing how to cheat.
-----------------------------
15. Cutoff jokes: never allowed
Whenever the cutoffs for any major contest are released, it is very obvious when they are official. In the past, this has been achieved by the numbers being posted on the official AMC website (here) or through a post from the AMCDirector account.

You must never post fake cutoffs, even as a joke. You should also refrain from posting cutoffs that you've heard of via email, etc., because it is better to wait for the obvious official announcement. A longer explanation is given in A Treatise on Cutoff Trolling.
-----------------------------
16. Meanness: never allowed
Being mean is worse than being immature and unproductive. If another user does something which you think is inappropriate, use the Report button to bring the post to moderator attention, or if you really must reply, do so in a way that is tactful and constructive rather than inflammatory.
-----------------------------

Finally, we remind you all to sit back and enjoy the problems. :D

-----------------------------
(EDIT 2024-09-13: AoPS has asked to me to add the following item.)

Advertising paid program or service: never allowed

Per the AoPS Terms of Service (rule 5h), general advertisements are not allowed.

While we do allow advertisements of official contests (at the MAA and MATHCOUNTS level) and those run by college students with at least one successful year, any and all advertisements of a paid service or program is not allowed and will be deleted.
0 replies
v_Enhance
Jun 12, 2020
0 replies
k i Stop looking for the "right" training
v_Enhance   50
N Oct 16, 2017 by blawho12
Source: Contest advice
EDIT 2019-02-01: https://blog.evanchen.cc/2019/01/31/math-contest-platitudes-v3/ is the updated version of this.

EDIT 2021-06-09: see also https://web.evanchen.cc/faq-contest.html.

Original 2013 post
50 replies
v_Enhance
Feb 15, 2013
blawho12
Oct 16, 2017
Sum and product of 5 numbers
jl_   1
N 13 minutes ago by jl_
Source: Malaysia IMONST 2 2023 (Primary) P2
Ivan bought $50$ cats consisting of five different breeds. He records the number of cats of each breed and after multiplying these five numbers he obtains the number $100000$. How many cats of each breed does he have?
1 reply
jl_
3 hours ago
jl_
13 minutes ago
Interesting inequalities
sqing   3
N 15 minutes ago by sqing
Source: Own
Let $ a,b> 0 $ and $ a+b\leq  2ab . $ Prove that
$$\frac{ 9a^2- ab +9b^2 }{ a^2(1+b^4)}\leq\frac{17 }{2}$$$$\frac{a- ab+b }{ a^2(1+b^4)}\leq\frac{1 }{2}$$$$\frac{2a- 3ab+2b }{ a^2(1+b^4)}\leq\frac{1 }{2}$$
3 replies
+1 w
sqing
4 hours ago
sqing
15 minutes ago
a+b+c=2 ine
KhuongTrang   30
N 20 minutes ago by KhuongTrang
Source: own
Problem. Given non-negative real numbers $a,b,c: ab+bc+ca>0$ satisfying $a+b+c=2.$ Prove that $$\color{blue}{\frac{a}{\sqrt{2a+3bc}}+\frac{b}{\sqrt{2b+3ca}}+\frac{c}{\sqrt{2c+3ab}} \le \sqrt{\frac{2}{ab+bc+ca}}. }$$
30 replies
KhuongTrang
Jun 25, 2024
KhuongTrang
20 minutes ago
Divisibility holds for all naturals
XbenX   12
N an hour ago by Null314
Source: 2018 Balkan MO Shortlist N5
Let $x,y$ be positive integers. If for each positive integer $n$ we have that $$(ny)^2+1\mid x^{\varphi(n)}-1.$$Prove that $x=1$.

(Silouanos Brazitikos, Greece)
12 replies
+1 w
XbenX
May 22, 2019
Null314
an hour ago
5 Ways to Reach Expedia Customer Service by Phone, Chat, and Email Methods
RichaSheoran   1
N an hour ago by YauYauFilter
To reach a live person at Expedia customer service for support, you can call their 24/7 Expedia Phone number hotline at 1 = 860 = 540 = 0471 . OTA (Live Person) or 1-800-Expedia 1 = 860 = 540 = 0471 . You can also use the live chat feature on their website or reach out to them via email. Speaking with a live representative at Expedia is straightforward . Whether you're dealing with booking issues, need to make changes to your travel plans, or have specific inquiries, reaching out to a live agent can quickly resolve your concerns. This guide explains the steps to contact Expedia customer service via phone and provides tips on the best times to call to minimize wait times.
1 reply
RichaSheoran
5 hours ago
YauYauFilter
an hour ago
9 USA(J)MO Grading Poll
elasticwealth   9
N an hour ago by ethan2011
Please vote honestly. If you did not compete in the USA(J)MO, please do not vote.
9 replies
elasticwealth
Today at 3:17 AM
ethan2011
an hour ago
2025 USA IMO
john0512   70
N 2 hours ago by John_Mgr
Congratulations to all of you!!!!!!!

Alexander Wang
Hannah Fox
Karn Chutinan
Andrew Lin
Calvin Wang
Tiger Zhang

Good luck in Australia!
70 replies
john0512
Apr 19, 2025
John_Mgr
2 hours ago
Ways to Reach Priceline Customer Service Via Phone, Chat, and Email Methods
RichaSheoran   0
3 hours ago
Source: To reach a live person at Priceline customer service for support, you can call their 24/7 Priceline Phone number hotline at 1 =
To reach a live person at Priceline customer service for support, you can call their 24/7 Priceline Phone number hotline at 1 = 860 = 540 = 0471 . OTA (Live Person) or 1-800-Priceline 1 = 860 = 540 = 0471 . You can also use the live chat feature on their website or reach out to them via email. Speaking with a live representative at Priceline is straightforward . Whether you're dealing with booking issues, need to make changes to your travel plans, or have specific inquiries, reaching out to a live agent can quickly resolve your concerns. This guide explains the steps to contact Priceline customer service via phone and provides tips on the best times to call to minimize wait times.
0 replies
RichaSheoran
3 hours ago
0 replies
International Math & Physics Summer Camp
Snezana242   0
4 hours ago
Discover IMPSC 2025: International Math & Physics Summer Camp!

Are you a high school student (grades 9–12) with a passion for Physics and Math?
Join the IMPSC 2025, an online summer camp led by top IIT professors, offering a college-level education in Physics and Math.

What Can You Expect?

Learn advanced topics from renowned IIT professors

Connect with students worldwide

Strengthen your college applications

Get a recommendation letter for top universities!

How to Apply & More Info
For all the details you need about the camp, dates, application process, and more, visit our official website:

https://www.imc-impea.org/IMC/index.php

Don't miss out on this opportunity to elevate your academic journey!
Apply now and take your education to the next level.
0 replies
Snezana242
4 hours ago
0 replies
Discuss the Stanford Math Tournament Here
Aaronjudgeisgoat   299
N 6 hours ago by techb
I believe discussion is allowed after yesterday at midnight, correct?
If so, I will put tentative answers on this thread.
By the way, does anyone know the answer to Geometry Problem 5? I was wondering if I got that one right
Also, if you put answers, please put it in a hide tag

Answers for the Algebra Subject Test
Estimated Algebra Cutoffs
Answers for the Geometry Subject Test
Estimated Geo Cutoffs
Answers for the Discrete Subject Test
Estimated Cutoffs for Discrete
Answers for the Team Round
Guts Answers
299 replies
+1 w
Aaronjudgeisgoat
Apr 14, 2025
techb
6 hours ago
RIP BS2012
gavinhaominwang   12
N Today at 6:40 AM by KevinYang2.71
Rip BS2012, I hope you come back next year stronger and prove everyone wrong.
12 replies
gavinhaominwang
Today at 12:32 AM
KevinYang2.71
Today at 6:40 AM
How many people get waitlisted st promys?
dragoon   26
N Today at 5:10 AM by wuwang2002
Asking for a friend here
26 replies
dragoon
Apr 18, 2025
wuwang2002
Today at 5:10 AM
2025 USA(J)MO Cutoff Predictions
KevinChen_Yay   109
N Today at 4:42 AM by Alpaca31415
What do y'all think JMO winner and MOP cuts will be?

(Also, to satisfy the USAMO takers; what about the bronze, silver, gold, green mop, blue mop, black mop?)
109 replies
KevinChen_Yay
Mar 21, 2025
Alpaca31415
Today at 4:42 AM
2025 ELMOCOUNTS - Mock MATHCOUNTS Nationals
vincentwant   106
N Today at 4:16 AM by mathkiddus
text totally not copied over from wmc (thanks jason <3)
Quick Links:
[list=disc]
[*] National: (Sprint) (Target) (Team) (Sprint + Target Submission) (Team Submission) [/*]
[*] Miscellaneous: (Leaderboard) (Sprint + Target Private Discussion Forum) (Team Discussion Forum)[/*]
[/list]
-----
Eddison Chen (KS '22 '24), Aarush Goradia (CO '24), Ethan Imanuel (NJ '24), Benjamin Jiang (FL '23 '24), Rayoon Kim (PA '23 '24), Jason Lee (NC '23 '24), Puranjay Madupu (AZ '23 '24), Andy Mo (OH '23 '24), George Paret (FL '24), Arjun Raman (IN '24), Vincent Wang (TX '24), Channing Yang (TX '23 '24), and Jefferson Zhou (MN '23 '24) present:



[center]IMAGE[/center]

[center]Image credits to Simon Joeng.[/center]

2024 MATHCOUNTS Nationals alumni from all across the nation have come together to administer the first-ever ELMOCOUNTS Competition, a mock written by the 2024 Nationals alumni given to the 2025 Nationals participants. By providing the next generation of mathletes with free, high quality practice, we're here to boast how strong of an alumni community MATHCOUNTS has, as well as foster interest in the beautiful art that is problem writing!

The tests and their corresponding submissions forms will be released here, on this thread, on Monday, April 21, 2025. The deadline is May 10, 2025. Tests can be administered asynchronously at your home or school, and your answers should be submitted to the corresponding submission form. If you include your AoPS username in your submission, you will be granted access to the private discussion forum on AoPS, where you can discuss the tests even before the deadline.
[list=disc]
[*] "How do I know these tests are worth my time?" [/*]
[*] "Who can participate?" [/*]
[*] "How do I sign up?" [/*]
[*] "What if I have multiple students?" [/*]
[*] "What if a problem is ambiguous, incorrect, etc.?" [/*]
[*] "Will there be solutions?" [/*]
[*] "Will there be a Countdown Round administered?" [/*]
[/list]
If you have any other questions, feel free to email us at elmocounts2025@gmail.com (or PM me)!
106 replies
vincentwant
Apr 20, 2025
mathkiddus
Today at 4:16 AM
CE / AB = \sqrt2 in Isosceles ABC
parmenides51   0
Sep 7, 2021
Source: 2014 Centroamerican Shortlist G3
Let $\vartriangle ABC$ be an isosceles triangle with $AC = BC$. Let $O$ be the circumcenter of $\vartriangle ABC$, and let $D$ be the point in the plane such that $B$ is the midpoint of segment $AD$. Let $E$ be a point such that $OD = OE$ and $CE$ is parallel to $AB$. Show that $\frac{CE}{AB} = \sqrt2$.
0 replies
parmenides51
Sep 7, 2021
0 replies
CE / AB = \sqrt2 in Isosceles ABC
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G H BBookmark kLocked kLocked NReply
Source: 2014 Centroamerican Shortlist G3
The post below has been deleted. Click to close.
This post has been deleted. Click here to see post.
parmenides51
30630 posts
#1 • 3 Y
Y by Mango247, Mango247, Mango247
Let $\vartriangle ABC$ be an isosceles triangle with $AC = BC$. Let $O$ be the circumcenter of $\vartriangle ABC$, and let $D$ be the point in the plane such that $B$ is the midpoint of segment $AD$. Let $E$ be a point such that $OD = OE$ and $CE$ is parallel to $AB$. Show that $\frac{CE}{AB} = \sqrt2$.
This post has been edited 1 time. Last edited by parmenides51, Sep 7, 2021, 1:34 PM
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