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

Example Input: Sentence: 'a bathroom with a tub connected to a pool with some sinks inside'. Replace the letter 'e' with 'b' in the sentence.
Example Output: a bathroom with a tub connbctbd to a pool with somb sinks insidb

Example Input: Sentence: 'a baby is holding and eating a banana'. Replace the letter 'i' with 'g' in the sentence.
Example Output: a baby gs holdgng and eatgng a banana

Example Input: Sentence: 'a couple of small giraffes that are next to each other'. Replace the letter 'i' with 'm' in the sentence.
Example Output:
a couple of small gmraffes that are next to each other