1.Ke7 of course. 1...a6 loses for Black.

I had to think it over. I didn't manage to calculate this position in my mind.

1.Ke7! Kc7
2.a6 Kc6
3.Kd8 Kd6
4.Kc8 Kc5
5.Kb8 Kb6
6.c5+ Kxc5
7.Kxa7 Kc6
8.Kb8 Kc5
9.a7 Kd4
10.a8=Q

1. Ke7! Kc7, 2. a6! Kb6, 3. Kd6 Kxa6, 4. c5 Kb7, 5. Kd7 a5, 6. c6+ Kb6, 7. c7 a4, 8. c8=Q and White wins