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

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 man eats food that is inside a banana peel'. Replace the letter 'n' with 'k' in the sentence.
Example Output: a mak eats food that is ikside a bakaka peel

Example Input: Sentence: 'some guys playing frisbee on some red surface'. Replace the letter 'y' with 'f' in the sentence.
Example Output:
some gufs plafing frisbee on some red surface