Click on the third or sixth rank to set the en passant target square.

EGTB: win in 4 half-moves

# move score
1 Kb4 win in 3 half-moves
2 Kb5 win in 3 half-moves
3 Kd4 loss in 8 half-moves
4 Kd5 loss in 8 half-moves
5 Kc4 loss in 6 half-moves
6 Kb6 loss in 2 half-moves
7 Kc6 loss in 2 half-moves
8 Kd6 loss in 2 half-moves