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

Example Input: Sentence: 'a black man is smoking a cigarette outside a shop'. Replace the letter 'm' with 'p' in the sentence.
Example Output: a black pan is spoking a cigarette outside a shop

Example Input: Sentence: 'a couple of kids with rackets on a court'. Replace the letter 'u' with 'd' in the sentence.
Example Output: a codple of kids with rackets on a codrt

Example Input: Sentence: 'woman sitting in a chair while holding a tennis racket'. Replace the letter 'h' with 'a' in the sentence.
Example Output:
woman sitting in a caair waile aolding a tennis racket