Skip Game

Alice and Bob are playing Skip Game, which consists of a one dimensional board of N cells numbered as 1,2,3….N. The ith cell on the board contains a number ai. In the game, Alice and Bob take turns. If a player is at a cell indexed i, then in the next step, the player moves forward by ai cells, ie the new position of the player will now be i + ai. Each player can start at any cell they want. The p