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

Input: Consider Input: Sentence: 'a large elephant standing outside beside a tree'. Replace the letter 'e' with 'y' in the sentence.

Output: a largy ylyphant standing outsidy bysidy a tryy

Input: Consider Input: Sentence: 'a photo of a river with a train bridge across it'. Replace the letter 'r' with 'f' in the sentence.

Output: a photo of a fivef with a tfain bfidge acfoss it

Input: Consider Input: Sentence: 'a woman on a surfboard is about to fall in thew ater'. Replace the letter 'r' with 'i' in the sentence.
Output: a woman on a suifboaid is about to fall in thew atei