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

Ex Input:
Sentence: 'a study features the color green and old-fashioned furniture'. Replace the letter 'e' with 'd' in the sentence.

Ex Output:
a study fdaturds thd color grddn and old-fashiondd furniturd

Ex Input:
Sentence: 'a computer, keyboard, and mouse sitting on a desk'. Replace the letter 's' with 'c' in the sentence.

Ex Output:
a computer, keyboard, and mouce citting on a deck

Ex Input:
Sentence: 'a group of people are standing on a busy street'. Replace the letter 's' with 'y' in the sentence.

Ex Output:
a group of people are ytanding on a buyy ytreet