Difference between revisions of "IMO Problems and Solutions, with authors"
m (→2000) |
m |
||
| Line 22: | Line 22: | ||
* [[1960 IMO Problems/Problem 5 | Problem 5]] proposed by Czechoslovakia | * [[1960 IMO Problems/Problem 5 | Problem 5]] proposed by Czechoslovakia | ||
* [[1960 IMO Problems/Problem 6 | Problem 6]] proposed by Bulgaria | * [[1960 IMO Problems/Problem 6 | Problem 6]] proposed by Bulgaria | ||
| − | * [[1960 IMO Problems/Problem 7 | Problem 7]] proposed by | + | * [[1960 IMO Problems/Problem 7 | Problem 7]] proposed by East Germany |
== 1961 == | == 1961 == | ||
| Line 31: | Line 31: | ||
* [[1961 IMO Problems/Problem 2 | Problem 2]] proposed by Poland | * [[1961 IMO Problems/Problem 2 | Problem 2]] proposed by Poland | ||
* [[1961 IMO Problems/Problem 3 | Problem 3]] proposed by Bulgaria | * [[1961 IMO Problems/Problem 3 | Problem 3]] proposed by Bulgaria | ||
| − | * [[1961 IMO Problems/Problem 4 | Problem 4]] proposed by | + | * [[1961 IMO Problems/Problem 4 | Problem 4]] proposed by East Germany |
* [[1961 IMO Problems/Problem 5 | Problem 5]] proposed by Czechoslovakia | * [[1961 IMO Problems/Problem 5 | Problem 5]] proposed by Czechoslovakia | ||
* [[1961 IMO Problems/Problem 6 | Problem 6]] proposed by Romania | * [[1961 IMO Problems/Problem 6 | Problem 6]] proposed by Romania | ||
| Line 44: | Line 44: | ||
* [[1962 IMO Problems/Problem 4 | Problem 4]] proposed by Romania | * [[1962 IMO Problems/Problem 4 | Problem 4]] proposed by Romania | ||
* [[1962 IMO Problems/Problem 5 | Problem 5]] proposed by Bulgaria | * [[1962 IMO Problems/Problem 5 | Problem 5]] proposed by Bulgaria | ||
| − | * [[1962 IMO Problems/Problem 6 | Problem 6]] proposed by | + | * [[1962 IMO Problems/Problem 6 | Problem 6]] proposed by East Germany |
* [[1962 IMO Problems/Problem 7 | Problem 7]] proposed by USSR | * [[1962 IMO Problems/Problem 7 | Problem 7]] proposed by USSR | ||
| Line 55: | Line 55: | ||
* [[1963 IMO Problems/Problem 3 | Problem 3]] proposed by Hungary | * [[1963 IMO Problems/Problem 3 | Problem 3]] proposed by Hungary | ||
* [[1963 IMO Problems/Problem 4 | Problem 4]] proposed by USSR | * [[1963 IMO Problems/Problem 4 | Problem 4]] proposed by USSR | ||
| − | * [[1963 IMO Problems/Problem 5 | Problem 5]] proposed by | + | * [[1963 IMO Problems/Problem 5 | Problem 5]] proposed by East Germany |
* [[1963 IMO Problems/Problem 6 | Problem 6]] proposed by Hungary | * [[1963 IMO Problems/Problem 6 | Problem 6]] proposed by Hungary | ||
| Line 110: | Line 110: | ||
* [[1968 IMO Problems/Problem 3 | Problem 3]] proposed by Bulgaria | * [[1968 IMO Problems/Problem 3 | Problem 3]] proposed by Bulgaria | ||
* [[1968 IMO Problems/Problem 4 | Problem 4]] proposed by Poland | * [[1968 IMO Problems/Problem 4 | Problem 4]] proposed by Poland | ||
| − | * [[1968 IMO Problems/Problem 5 | Problem 5]] proposed by | + | * [[1968 IMO Problems/Problem 5 | Problem 5]] proposed by East Germany |
* [[1968 IMO Problems/Problem 6 | Problem 6]] proposed by United Kingdom | * [[1968 IMO Problems/Problem 6 | Problem 6]] proposed by United Kingdom | ||
| Line 117: | Line 117: | ||
* [[1969 IMO]] | * [[1969 IMO]] | ||
* [[1969 IMO Problems]] | * [[1969 IMO Problems]] | ||
| − | * [[1969 IMO Problems/Problem 1 | Problem 1]] proposed by | + | * [[1969 IMO Problems/Problem 1 | Problem 1]] proposed by East Germany |
* [[1969 IMO Problems/Problem 2 | Problem 2]] proposed by Hungary | * [[1969 IMO Problems/Problem 2 | Problem 2]] proposed by Hungary | ||
* [[1969 IMO Problems/Problem 3 | Problem 3]] proposed by Poland | * [[1969 IMO Problems/Problem 3 | Problem 3]] proposed by Poland | ||
| Line 209: | Line 209: | ||
* [[1977 IMO Problems/Problem 3 | Problem 3]] proposed by Netherlands | * [[1977 IMO Problems/Problem 3 | Problem 3]] proposed by Netherlands | ||
* [[1977 IMO Problems/Problem 4 | Problem 4]] proposed by United Kingdom | * [[1977 IMO Problems/Problem 4 | Problem 4]] proposed by United Kingdom | ||
| − | * [[1977 IMO Problems/Problem 5 | Problem 5]] proposed by | + | * [[1977 IMO Problems/Problem 5 | Problem 5]] proposed by East Germany |
* [[1977 IMO Problems/Problem 6 | Problem 6]] proposed by Bulgaria | * [[1977 IMO Problems/Problem 6 | Problem 6]] proposed by Bulgaria | ||
| Line 232: | Line 232: | ||
* [[1979 IMO Problems/Problem 1 | Problem 1]] proposed by USA | * [[1979 IMO Problems/Problem 1 | Problem 1]] proposed by USA | ||
* [[1979 IMO Problems/Problem 1 | Problem 1]] proposed by Israel | * [[1979 IMO Problems/Problem 1 | Problem 1]] proposed by Israel | ||
| − | * [[1979 IMO Problems/Problem 1 | Problem 1]] proposed by | + | * [[1979 IMO Problems/Problem 1 | Problem 1]] proposed by East Germany |
== 1980 == | == 1980 == | ||
| Line 299: | Line 299: | ||
* [[1986 IMO Problems/Problem 1 | Problem 1]] proposed by Western Germany | * [[1986 IMO Problems/Problem 1 | Problem 1]] proposed by Western Germany | ||
* [[1986 IMO Problems/Problem 2 | Problem 2]] proposed by Gengzhe Chang and Dongxu Qi, China | * [[1986 IMO Problems/Problem 2 | Problem 2]] proposed by Gengzhe Chang and Dongxu Qi, China | ||
| − | * [[1986 IMO Problems/Problem 3 | Problem 3]] proposed by Elias Wegert, | + | * [[1986 IMO Problems/Problem 3 | Problem 3]] proposed by Elias Wegert, East Germany |
* [[1986 IMO Problems/Problem 4 | Problem 4]] proposed by Iceland | * [[1986 IMO Problems/Problem 4 | Problem 4]] proposed by Iceland | ||
* [[1986 IMO Problems/Problem 5 | Problem 5]] proposed by United Kingdom | * [[1986 IMO Problems/Problem 5 | Problem 5]] proposed by United Kingdom | ||
| − | * [[1986 IMO Problems/Problem 6 | Problem 6]] proposed by Konrad Engel, | + | * [[1986 IMO Problems/Problem 6 | Problem 6]] proposed by Konrad Engel, East Germany |
== 1987 == | == 1987 == | ||
| Line 312: | Line 312: | ||
* [[1987 IMO Problems/Problem 3 | Problem 3]] proposed by Western Germany | * [[1987 IMO Problems/Problem 3 | Problem 3]] proposed by Western Germany | ||
* [[1987 IMO Problems/Problem 4 | Problem 4]] proposed by Vietnam | * [[1987 IMO Problems/Problem 4 | Problem 4]] proposed by Vietnam | ||
| − | * [[1987 IMO Problems/Problem 5 | Problem 5]] proposed by | + | * [[1987 IMO Problems/Problem 5 | Problem 5]] proposed by East Germany |
* [[1987 IMO Problems/Problem 6 | Problem 6]] proposed by V.F.Lev, USSR | * [[1987 IMO Problems/Problem 6 | Problem 6]] proposed by V.F.Lev, USSR | ||
Revision as of 14:12, 27 January 2007
This page lists the authors of the problems of the IMO.
Contents
- 1 1959
- 2 1960
- 3 1961
- 4 1962
- 5 1963
- 6 1964
- 7 1965
- 8 1966
- 9 1967
- 10 1968
- 11 1969
- 12 1970
- 13 1971
- 14 1972
- 15 1973
- 16 1974
- 17 1975
- 18 1976
- 19 1977
- 20 1978
- 21 1979
- 22 1980
- 23 1981
- 24 1982
- 25 1983
- 26 1984
- 27 1985
- 28 1986
- 29 1987
- 30 1988
- 31 1989
- 32 1990
- 33 1991
- 34 1992
- 35 1993
- 36 1994
- 37 1995
- 38 1996
- 39 1997
- 40 1998
- 41 1999
- 42 2000
- 43 2001
- 44 2002
- 45 2003
- 46 2004
- 47 2005
- 48 2006
- 49 See also
1959
- 1959 IMO
- 1959 IMO Problems
- Problem 1 proposed by Poland
- Problem 2 proposed by Romania
- Problem 3 proposed by Hungary
- Problem 4 proposed by Hungary
- Problem 5 proposed by Romania
- Problem 6 proposed by Czechoslovakia
1960
- 1960 IMO
- 1960 IMO Problems
- Problem 1 proposed by Bulgaria
- Problem 2 proposed by Hungary
- Problem 3 proposed by Romania
- Problem 4 proposed by Hungary
- Problem 5 proposed by Czechoslovakia
- Problem 6 proposed by Bulgaria
- Problem 7 proposed by East Germany
1961
- 1961 IMO
- 1961 IMO Problems
- Problem 1 proposed by Hungary
- Problem 2 proposed by Poland
- Problem 3 proposed by Bulgaria
- Problem 4 proposed by East Germany
- Problem 5 proposed by Czechoslovakia
- Problem 6 proposed by Romania
1962
- 1962 IMO
- 1962 IMO Problems
- Problem 1 proposed by Poland
- Problem 2 proposed by Hungary
- Problem 3 proposed by Czechoslovakia
- Problem 4 proposed by Romania
- Problem 5 proposed by Bulgaria
- Problem 6 proposed by East Germany
- Problem 7 proposed by USSR
1963
- 1963 IMO
- 1963 IMO Problems
- Problem 1 proposed by Czechoslovakia
- Problem 2 proposed by USSR
- Problem 3 proposed by Hungary
- Problem 4 proposed by USSR
- Problem 5 proposed by East Germany
- Problem 6 proposed by Hungary
1964
- 1964 IMO
- 1964 IMO Problems
- Problem 1 proposed by Czechoslovakia
- Problem 2 proposed by Hungary
- Problem 3 proposed by Yugoslavia
- Problem 4 proposed by Hungary
- Problem 5 proposed by Romania
- Problem 6 proposed by Poland
1965
- 1965 IMO
- 1965 IMO Problems
- Problem 1 proposed by Yugoslavia
- Problem 2 proposed by Poland
- Problem 3 proposed by Czechoslovakia
- Problem 4 proposed by USSR
- Problem 5 proposed by Romania
- Problem 6 proposed by Poland
1966
- 1966 IMO
- 1966 IMO Problems
- Problem 1 proposed by USSR
- Problem 2 proposed by Hungary
- Problem 3 proposed by Bulgaria
- Problem 4 proposed by Yugoslavia
- Problem 5 proposed by Czechoslovakia
- Problem 6 proposed by Poland
1967
- 1967 IMO
- 1967 IMO Problems
- Problem 1 proposed by Poland
- Problem 2 proposed by Czechoslovakia
- Problem 3 proposed by United Kingdom
- Problem 4 proposed by Italy
- Problem 5 proposed by USSR
- Problem 6 proposed by Hungary
1968
- 1968 IMO
- 1968 IMO Problems
- Problem 1 proposed by Romania
- Problem 2 proposed by Czechoslovakia
- Problem 3 proposed by Bulgaria
- Problem 4 proposed by Poland
- Problem 5 proposed by East Germany
- Problem 6 proposed by United Kingdom
1969
- 1969 IMO
- 1969 IMO Problems
- Problem 1 proposed by East Germany
- Problem 2 proposed by Hungary
- Problem 3 proposed by Poland
- Problem 4 proposed by Netherlands
- Problem 5 proposed by Mongolia
- Problem 6 proposed by USSR
1970
- 1970 IMO
- 1970 IMO Problems
- Problem 1 proposed by Poland
- Problem 1 proposed by Romania
- Problem 1 proposed by Sweden
- Problem 1 proposed by Czechoslovakia
- Problem 1 proposed by Bulgaria
- Problem 1 proposed by USSR
1971
- 1971 IMO
- 1971 IMO Problems
- Problem 1 proposed by Hungary
- Problem 2 proposed by USSR
- Problem 3 proposed by Poland
- Problem 4 proposed by Netherlands
- Problem 5 proposed by Bulgaria
- Problem 6 proposed by Sweden
1972
- 1972 IMO
- 1972 IMO Problems
- Problem 1 proposed by USSR
- Problem 2 proposed by Netherlands
- Problem 3 proposed by United Kingdom
- Problem 4 proposed by Netherlands
- Problem 5 proposed by Bulgaria
- Problem 6 proposed by United Kingdom
1973
- 1973 IMO
- 1973 IMO Problems
- Problem 1 proposed by Czechoslovakia
- Problem 2 proposed by Poland
- Problem 3 proposed by Sweden
- Problem 4 proposed by Yugoslavia
- Problem 5 proposed by Poland
- Problem 6 proposed by Sweden
1974
- 1974 IMO
- 1974 IMO Problems
- Problem 1 proposed by USA
- Problem 2 proposed by Finland
- Problem 3 proposed by Romania
- Problem 4 proposed by Bulgaria
- Problem 5 proposed by Netherlands
- Problem 6 proposed by Sweden
1975
- 1975 IMO
- 1975 IMO Problems
- Problem 1 proposed by Czechoslovakia
- Problem 2 proposed by United Kingdom
- Problem 3 proposed by Netherlands
- Problem 4 proposed by USSR
- Problem 5 proposed by USSR
- Problem 6 proposed by United Kingdom
1976
- 1976 IMO
- 1976 IMO Problems
- Problem 1 proposed by Czechoslovakia
- Problem 2 proposed by Finland
- Problem 3 proposed by Netherlands
- Problem 4 proposed by USA
- Problem 5 proposed by Netherlands
- Problem 6 proposed by United Kingdom
1977
- 1977 IMO
- 1977 IMO Problems
- Problem 1 proposed by Netherlands
- Problem 2 proposed by Vietnam
- Problem 3 proposed by Netherlands
- Problem 4 proposed by United Kingdom
- Problem 5 proposed by East Germany
- Problem 6 proposed by Bulgaria
1978
- 1978 IMO
- 1978 IMO Problems
- Problem 1 proposed by Cuba
- Problem 2 proposed by USA
- Problem 3 proposed by United Kingdom
- Problem 4 proposed by USA
- Problem 5 proposed by France
- Problem 6 proposed by Netherlands
1979
- 1979 IMO
- 1979 IMO Problems
- Problem 1 proposed by Western Germany
- Problem 1 proposed by Bulgaria
- Problem 1 proposed by USSR
- Problem 1 proposed by USA
- Problem 1 proposed by Israel
- Problem 1 proposed by East Germany
1980
1981
- 1981 IMO
- 1981 IMO Problems
- Problem 1 proposed by United Kingdom
- Problem 2 proposed by Western Germany
- Problem 3 proposed by Netherlands
- Problem 4 proposed by Belgium
- Problem 5 proposed by USSR
- Problem 6 proposed by Finland
1982
- 1982 IMO
- 1982 IMO Problems
- Problem 1 proposed by United Kingdom
- Problem 2 proposed by Netherlands
- Problem 3 proposed by A.Grishkov, USSR
- Problem 4 proposed by United Kingdom
- Problem 5 proposed by Netherlands
- Problem 6 proposed by Vietnam
1983
- 1983 IMO
- 1983 IMO Problems
- Problem 1 proposed by United Kingdom
- Problem 2 proposed by I.F.Sharygin, USSR
- Problem 3 proposed by Western Germany
- Problem 4 proposed by Belgium
- Problem 5 proposed by Poland
- Problem 6 proposed by USA
1984
- 1984 IMO
- 1984 IMO Problems
- Problem 1 proposed by Western Germany
- Problem 2 proposed by Netherlands
- Problem 3 proposed by Romania
- Problem 4 proposed by Romania
- Problem 5 proposed by Mongolia
- Problem 6 proposed by Poland
1985
- 1985 IMO
- 1985 IMO Problems
- Problem 1 proposed by United Kingdom
- Problem 2 proposed by Australia
- Problem 3 proposed by Netherlands
- Problem 4 proposed by Mongolia
- Problem 5 proposed by USSR
- Problem 6 proposed by Sweden
1986
- 1986 IMO
- 1986 IMO Problems
- Problem 1 proposed by Western Germany
- Problem 2 proposed by Gengzhe Chang and Dongxu Qi, China
- Problem 3 proposed by Elias Wegert, East Germany
- Problem 4 proposed by Iceland
- Problem 5 proposed by United Kingdom
- Problem 6 proposed by Konrad Engel, East Germany
1987
- 1987 IMO
- 1987 IMO Problems
- Problem 1 proposed by Western Germany
- Problem 2 proposed by I.A.Kushnir, USSR
- Problem 3 proposed by Western Germany
- Problem 4 proposed by Vietnam
- Problem 5 proposed by East Germany
- Problem 6 proposed by V.F.Lev, USSR
1988
- 1988 IMO
- 1988 IMO Problems
- Problem 1 proposed by Lucien Kieffer, Luxembourg
- Problem 2 proposed by Czechoslovakia
- Problem 3 proposed by United Kingdom
- Problem 4 proposed by Ireland
- Problem 5 proposed by Greece
- Problem 6 proposed by Western Germany
1989
- 1989 IMO
- 1989 IMO Problems
- Problem 1 proposed by Philippines
- Problem 2 proposed by Australia
- Problem 3 proposed by Hendrikus Gerardus Derksen, Netherlands
- Problem 4 proposed by Iceland
- Problem 5 proposed by Sweden
- Problem 6 proposed by Marcin Kuczma, Poland
1990
- 1990 IMO
- 1990 IMO Problems
- Problem 1 proposed by India
- Problem 2 proposed by Czechoslovakia
- Problem 3 proposed by Laurentin Panaitopol, Romania
- Problem 4 proposed by Turkey
- Problem 5 proposed by Germany
- Problem 6 proposed by Hendrikus Gerardus Derksen, Netherlands
1991
- 1991 IMO
- 1991 IMO Problems
- Problem 1 proposed by USSR
- Problem 2 proposed by Romania
- Problem 3 proposed by Chengzhang Li, China
- Problem 4 proposed by USA
- Problem 5 proposed by Johan Yebbou, France
- Problem 6 proposed by Hendrikus Gerardus Derksen, Netherlands
1992
- 1992 IMO
- 1992 IMO Problems
- Problem 1 proposed by New Zealand
- Problem 2 proposed by India
- Problem 3 proposed by Chengzhang Li, China
- Problem 4 proposed by Johan Yebbou, France
- Problem 5 proposed by Italy
- Problem 6 proposed by Tony Gardiner, United Kingdom
1993
- 1993 IMO
- 1993 IMO Problems
- Problem 1 proposed by Ireland
- Problem 2 proposed by David Monk, United Kingdom
- Problem 3 proposed by Finland
- Problem 4 proposed by Macedonia
- Problem 5 proposed by Elias Wegert, Germany
- Problem 6 proposed by Nicholas de Bruijn, Netherlands
1994
- 1994 IMO
- 1994 IMO Problems
- Problem 1 proposed by Vincent Lafforgue, France
- Problem 2 proposed by Hans Lausch, Australia and Armenia independently
- Problem 3 proposed by Romania
- Problem 4 proposed by Australia
- Problem 5 proposed by United Kingdom
- Problem 6 proposed by Finland
1995
- 1995 IMO
- 1995 IMO Problems
- Problem 1 proposed by Bulgaria
- Problem 2 proposed by Nazar Agakhanov, Russia
- Problem 3 proposed by Karel Horak, Czech Republic
- Problem 4 proposed by Marcin Kuczma, Poland
- Problem 5 proposed by New Zealand
- Problem 6 proposed by Marcin Kuczma, Poland
1996
- 1996 IMO
- 1996 IMO Problems
- Problem 1 proposed by Finland
- Problem 2 proposed by Canada
- Problem 3 proposed by Romania
- Problem 4 proposed by Alexander Golovanov, Russia
- Problem 5 proposed by Nairi Sedrakyan, Armenia
- Problem 6 proposed by Laurent Rosaz, France
1997
- 1997 IMO
- 1997 IMO Problems
- Problem 1 proposed by Belarus
- Problem 2 proposed by David Monk, United Kingdom
- Problem 3 proposed by Russia
- Problem 4 proposed by Iran
- Problem 5 proposed by Czech Republic
- Problem 6 proposed by Giedrius Alkauskas, Lithuania
1998
- 1998 IMO
- 1998 IMO Problems
- Problem 1 proposed by Charles Leytem, Luxembourg
- Problem 2 proposed by India
- Problem 3 proposed by Belarus
- Problem 4 proposed by David Monk, United Kingdom
- Problem 5 proposed by Ukraine
- Problem 6 proposed by Nikolai Nikolov and Oleg Mushkarov, Bulgaria
1999
- 1999 IMO
- 1999 IMO Problems
- Problem 1 proposed by Jan Villemson, Estonia
- Problem 2 proposed by Marcin Kuczma, Poland
- Problem 3 proposed by E. Barabanov and I. Voronovich, Belarus
- Problem 4 proposed by Taiwan
- Problem 5 proposed by P. Kozhevnikov, Russia
- Problem 6 proposed by Japan
2000
- 2000 IMO
- 2000 IMO Problems
- Problem 1 proposed by Sergei Berlov, Russia
- Problem 2 proposed by Titu Andreescu, USA
- Problem 3 proposed by Belarus
- Problem 4 proposed by Sandor Dobos, Hungary
- Problem 5 proposed by Valerii Senderov, Russia
- Problem 6 proposed by Lev and Tatiana Emelianovii, Russia
2001
- 2001 IMO
- 2001 IMO Problems
- Problem 1 proposed by Hojoo Lee, South Korea
- Problem 2 proposed by Hojoo Lee, South Korea
- Problem 3 proposed by Christian Bey, Germany
- Problem 4 proposed by Bill Sands, Canada
- Problem 5 proposed by Toshio Seimiya, Japan (see Crux Mathematicorum problem 2501)
- Problem 6 proposed by Alexander Ivanov, Bulgaria
2002
- 2002 IMO
- 2002 IMO Problems
- Problem 1 proposed by Federico Ardila, Colombia
- Problem 2 proposed by Hojoo Lee, South Korea
- Problem 3 proposed by Laurentin Panaitopol, Romania
- Problem 4 proposed by Mihai Manea, Romania
- Problem 5 proposed by B.J.Venkatachala, India
- Problem 6 proposed by Vyacheslav Yasinskiy, Ukraine
2003
- 2003 IMO
- 2003 IMO Problems
- Problem 1 proposed by Carlos Gustavo Moreira, Brazil
- Problem 2 proposed by Bulgaria
- Problem 3 proposed by Poland
- Problem 4 proposed by Finland
- Problem 5 proposed by Ireland
- Problem 6 proposed by Johan Yebbou, France
2004
- 2004 IMO
- 2004 IMO Problems
- Problem 1 proposed by Valentin Vornicu and Dinu Serbanescu, Romania
- Problem 2 proposed by Hojoo Lee, South Korea
- Problem 3 proposed by Jan Villemson, Estonia
- Problem 4 proposed by Hojoo Lee, South Korea
- Problem 5 proposed by Poland
- Problem 6 proposed by Mohsen Jamali, Iran
2005
- 2005 IMO
- 2005 IMO Problems
- Problem 1 proposed by Bogdan Enescu, Romania
- Problem 2 proposed by Nicholas de Bruijn, Netherlands
- Problem 3 proposed by Hojoo Lee, South Korea
- Problem 4 proposed by Poland
- Problem 5 proposed by Poland
- Problem 6 proposed by Radu Gologan, Romania
2006
- 2006 IMO
- 2006 IMO Problems
- Problem 1 proposed by Hojoo Lee, South Korea
- Problem 2 proposed by Dušan Đukić, Serbia
- Problem 3 proposed by Ireland
- Problem 4 proposed by Zuming Feng, USA
- Problem 5 proposed by Romania
- Problem 6 proposed by Dušan Đukić, Serbia
