MathDB
whoever makes the gcd loses

Source: 239 2015 J6

May 15, 2020
combinatoricsgamegame strategynumber theory

Problem Statement

The numbers 1,2,3,,10001,2,3,\dots,1000 are written on the board. Patya and Vassya are playing a game. They take turn alternatively erasing a number from the board. Patya begins. If after a turn all numbers (maybe one) on the board be divisible by a natural number greater than 11 the player who last played loses. If after some number of steps the only remaining number on the board be 11 then they call it a draw. Determine the result of the game if they both play their best.