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

Ex Input:
Sentence: 'a group of three giraffes standing around a fence'. Replace the letter 't' with 'a' in the sentence.

Ex Output:
a group of ahree giraffes saanding around a fence


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: 'several zebras on a plain, grazing and congregating'. Replace the letter 'z' with 'l' in the sentence.

Ex Output:

several lebras on a plain, graling and congregating