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

Ex Input:
Sentence: 'street signs hanging next to a traffic light on a city street'. Replace the letter 'g' with 'm' in the sentence.

Ex Output:
street simns hanminm next to a traffic limht on a city street

Ex Input:
Sentence: 'giraffes behind a fence in the trees'. Replace the letter 'h' with 'l' in the sentence.

Ex Output:
giraffes belind a fence in tle trees

Ex Input:
Sentence: 'a crowd of people on a sandy beach flying kites'. Replace the letter 'a' with 'g' in the sentence.

Ex Output:
g crowd of people on g sgndy begch flying kites