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CentroAmerican
2016 CentroAmerican
4
4
Part of
2016 CentroAmerican
Problems
(1)
Game with coprime integers
Source: Centroamerican 2016, problem 4
6/21/2016
The number "3" is written on a board. Ana and Bernardo take turns, starting with Ana, to play the following game. If the number written on the board is
n
n
n
, the player in his/her turn must replace it by an integer
m
m
m
coprime with
n
n
n
and such that
n
<
m
<
n
2
n<m<n^2
n
<
m
<
n
2
. The first player that reaches a number greater or equal than 2016 loses. Determine which of the players has a winning strategy and describe it.
games
number theory