Amy and Bob play the game. At the beginning, Amy writes down a positive integer on the board. Then the players take moves in turn, Bob moves first. On any move of his, Bob replaces the number \(n\) on the blackboard with a number of the form \(n-a^2\), where \(a\) is a positive integer. On any move of hers, Amy replaces the number \(n\) on the blackboard with a number of the form \(n^k\), where \(k\) is a positive integer. Bob wins if the number on the board becomes zero. Can Amy prevent Bob’s win?