In this task, you need to replace a letter in the sentence with another given letter.

Ex Input:
Sentence: 'an airplane moves through the skies above a snowy mountain range'. Replace the letter 'l' with 's' in the sentence.

Ex Output:
an airpsane moves through the skies above a snowy mountain range

Ex Input:
Sentence: 'a open entrance leading to a set of closed doors'. Replace the letter 'd' with 'f' in the sentence.

Ex Output:
a open entrance leafing to a set of closef foors

Ex Input:
Sentence: 'a pie filled with rigatoni pasta sitting on a counter'. Replace the letter 's' with 'f' in the sentence.

Ex Output:
a pie filled with rigatoni pafta fitting on a counter