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

Ex Input:
Sentence: 'a person holding a green cell phone in a classroom with many desks'. Replace the letter 'k' with 'w' in the sentence.

Ex Output:
a person holding a green cell phone in a classroom with many desws


Ex Input:
Sentence: 'a man wearing a hat has his cell phone to his ear'. Replace the letter 'g' with 'w' in the sentence.

Ex Output:
a man wearinw a hat has his cell phone to his ear


Ex Input:
Sentence: 'a couple of birds stand on top of a rock'. Replace the letter 'o' with 'd' in the sentence.

Ex Output:

a cduple df birds stand dn tdp df a rdck