Y by Mango247
There are
clubs
with non-empty members. For any triplet of members
with
, two of them are friend and two of them are not friend (here the friend relationship is bidirectional). Prove that one of
these statements must be true
1. There exist one student from
that knows all students from 
2. There exist one student from
that knows all students from 
3. There exist one student from
that knows all students from 




these statements must be true
1. There exist one student from


2. There exist one student from


3. There exist one student from

