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

Ex Input:
Sentence: 'many street signs in front of a building while it is snowing'. Replace the letter 'r' with 'x' in the sentence.

Ex Output:
many stxeet signs in fxont of a building while it is snowing


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: 'bowls of cut vegetables are in a kitchen'. Replace the letter 'b' with 'd' in the sentence.

Ex Output:

dowls of cut vegetadles are in a kitchen