Puzzle 4  (2)

White has plenty of pieces in reserve; Black has only one piece left to play with - and a last GIPF on g3 that can easily be attacked. How many moves does White minimally need to win the game?

Possibility 1: 1 move
Possibility 2: 2 moves
Possibility 3: 3 moves
Possibility 4: 4 moves
Possibility 5: White will need more than 4 moves to win