MEMO 2010 pojedinačno problem 2
Kvaliteta:
Avg: 4,0Težina:
Avg: 5,3 All positive divisors of a positive integer
are written on a blackboard. Two players
and
play the following game taking alternate moves. In the firt move, the player
erases
. If the last erased number is
, then the next player erases either a divisor of
or a multiple of
. The player who cannot make a move loses. Determine all numbers
for which
can win independently of the moves of
.











Izvor: Srednjoeuropska matematička olimpijada 2010, pojedinačno natjecanje, problem 2