How do the two men proceed after Vizintin goes back to the Fairchild?

After Vizintin left them, Parrado and Canessa took a break to replenish their energy and then continued their ascent. Parrado (Nando) took the lead position on the expedition. The extreme altitude wore on their bodies and rendered them exhausted. During their hike, Canessa prayed continuously to God. They made it up the mountain and down the other side.