Gambles are independent, and each one results in the player being equally likely to win or lose

Question:

Gambles are independent, and each one results in the player being equally likely to win or lose 1 unit. Let W denote the net winnings of a gambler whose strategy is to stop gambling immediately after his first win. Find
(a) P{W > 0}
(b) P{W < 0}
(c) E[W]