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

Ex Input:
Sentence: 'a person that is sitting under an umbrella'. Replace the letter 'a' with 'l' in the sentence.

Ex Output:
l person thlt is sitting under ln umbrelll


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 bathroom with a small sink and toilet'. Replace the letter 'e' with 'u' in the sentence.

Ex Output:

a bathroom with a small sink and toilut