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

Example Input: Sentence: 'a person holding a small remote key chain'. Replace the letter 'n' with 'j' in the sentence.
Example Output: a persoj holdijg a small remote key chaij

Example Input: Sentence: 'a black cat is sniffing a glass bottle'. Replace the letter 'c' with 'f' in the sentence.
Example Output: a blafk fat is sniffing a glass bottle

Example Input: Sentence: 'a dog with his tongue out riding on a skateboard'. Replace the letter 's' with 'b' in the sentence.
Example Output:
a dog with hib tongue out riding on a bkateboard