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

Ex Input:
Sentence: 'lose up of various trays of croissants and muffins'. Replace the letter 'n' with 'f' in the sentence.

Ex Output:
lose up of various trays of croissafts afd muffifs

Ex Input:
Sentence: 'a woman holding a tennis racket getting ready to hit a tennis ball'. Replace the letter 'r' with 'l' in the sentence.

Ex Output:
a woman holding a tennis lacket getting leady to hit a tennis ball

Ex Input:
Sentence: 'several horses standing and lying down in a grassy field'. Replace the letter 'v' with 'e' in the sentence.

Ex Output:
seeeral horses standing and lying down in a grassy field