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

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

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

Input: Consider Input: Sentence: 'a person is looking out of a large window'. Replace the letter 'o' with 'p' in the sentence.

Output: a perspn is lppking put pf a large windpw

Input: Consider Input: Sentence: 'a bus on a street next to a tree'. Replace the letter 'r' with 'n' in the sentence.
Output: a bus on a stneet next to a tnee