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

Example Input: Sentence: 'two kids sitting on a  child's bed and smiling'. Replace the letter 't' with 's' in the sentence.
Example Output: swo kids sissing on a  child's bed and smiling

Example Input: Sentence: 'three men in a park playing a sport'. Replace the letter 'p' with 'w' in the sentence.
Example Output: three men in a wark wlaying a swort

Example Input: Sentence: 'a little baby has a phone in its mouth'. Replace the letter 'e' with 'i' in the sentence.
Example Output:
a littli baby has a phoni in its mouth