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

Ex Input:
Sentence: 'a geoup of people on bicycles coming down a street'. Replace the letter 'i' with 'x' in the sentence.

Ex Output:
a geoup of people on bxcycles comxng down a street

Ex Input:
Sentence: 'a woman sitting in front of a laptop computer'. Replace the letter 'u' with 'o' in the sentence.

Ex Output:
a woman sitting in front of a laptop compoter

Ex Input:
Sentence: 'a zebra bending its neck to eat something on the ground'. Replace the letter 'i' with 'z' in the sentence.

Ex Output:
a zebra bendzng zts neck to eat somethzng on the ground