Adding game.
Source: Spain Mathematical Olympiad 2020 P4
July 15, 2020
Spaincombinatoricsgame
Problem Statement
Ana and Benito play a game which consists of turns. Initially, there are cards on the table, numbered from to , and Ana possesses an extra card with number . In the -th turn, the player that doesn't possess card chooses whether to take the card with number or to give it to the other player. The number in each card indicates its value in points. At the end of the game whoever has most points wins. Determine whether one player has a winning strategy or whether both players can force a tie, and describe the strategy.