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

Example Input: Sentence: 'a group of people on a beach flying a kite'. Replace the letter 'p' with 'i' in the sentence.
Example Output: a groui of ieoile on a beach flying a kite

Example Input: Sentence: 'a large clock tower next to a building on a street'. Replace the letter 'c' with 'n' in the sentence.
Example Output: a large nlonk tower next to a building on a street

Example Input: Sentence: 'a red plus sign over a toilet, near a sink'. Replace the letter 'r' with 'o' in the sentence.
Example Output:
a oed plus sign oveo a toilet, neao a sink