MathDB

(Game) Károly and Dezso wish to count up to

m

and play the following game in the meantime: they start from

0

and the two players can add a positive number less than

13

to the previous number, taking turns. However because of their superstition, if one of them added

x

, then the other one in the next step cannot add

13-x

. Whoever reaches (or surpasses)

m

first, loses. Defeat the organisers in this game twice in a row! A starting position will be given and then you can decide whether you want to go first or second.

Problem Statement