1.Kg7! h4 (or 1...Kb6 Kf6 2.Kxc6 Kg5)
2... h3 leads to 3.Ke6 h2 4.c7 Kb7 5.Kd7 and White draws.
3... h3 leads to 4.Kd6 h2 5.c7 and White draws.
This classic study is an excellent illustration of the fact that the King can take many alternative routes to the same square, each of which use the same amount of tempi. By moving to the center of the board while still chasing the Black pawn, White is able to create a promotion threat of his own. If Black ignores this threat, both pawns will queen and the ending will be drawn, but if Black spends moves with his king to stop the white c-pawn, White's king will be able to catch the h-pawn.