Solution3:
1 f3 Nxa4?  2 Kc2 Ke7  3 Kb3  Nc5 +  4 Bxc5 bxc5  5 Ka4 Kd7 6 Kxa5 Kc8
7 Ka6 Kb8 8 b6 cxb6 9 Kxb6 and with the opposition the white king eats
blacks pawns