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

Example Input: Sentence: 'a double decker bus stopped outside a station on a street'. Replace the letter 'c' with 'y' in the sentence.
Example Output: a double deyker bus stopped outside a station on a street

Example Input: Sentence: 'the two boys are eating large carrots while sitting on a blanket'. Replace the letter 'a' with 'q' in the sentence.
Example Output: the two boys qre eqting lqrge cqrrots while sitting on q blqnket

Example Input: Sentence: 'two men pose wearing ties and fedora hats'. Replace the letter 'e' with 'w' in the sentence.
Example Output:
two mwn posw wwaring tiws and fwdora hats