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

Ex Input:
Sentence: 'people watching a kite being flown with a sky background'. Replace the letter 'a' with 'b' in the sentence.

Ex Output:
people wbtching b kite being flown with b sky bbckground


Ex Input:
Sentence: 'a group of young adults are engaged in outdoor exercise'. Replace the letter 'g' with 'n' in the sentence.

Ex Output:
a nroup of younn adults are ennaned in outdoor exercise


Ex Input:
Sentence: 'a man grins as he picks up a laptop computer'. Replace the letter 'u' with 'w' in the sentence.

Ex Output:

a man grins as he picks wp a laptop compwter