MathDB
Problems
Contests
National and Regional Contests
France Contests
France Pre-TST
2005 France Pre-TST
3
3
Part of
2005 France Pre-TST
Problems
(1)
French pre-TST-2004/2005 #3
Source: Me
12/20/2004
Two players write alternatively some integers on the blackboard. The rules are the following : - The first player write
1
1
1
. - At each of the other turns, the player has to write
a
+
1
a+1
a
+
1
or
2
a
2a
2
a
where
a
a
a
is any number already wrote in the blackboard and
2
a
≤
1000.
2a \leq 1000.
2
a
≤
1000.
- One cannot write a number which has already been written, and no number is erased. - The player who writes
1000
1000
1000
is the winner. Determine which player has a winning strategy. Pierre.