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

Ex Input:
Sentence: 'a hand held game or older cell phone'. Replace the letter 'o' with 'c' in the sentence.

Ex Output:
a hand held game cr clder cell phcne

Ex Input:
Sentence: 'a small bird perched on a open window'. Replace the letter 'e' with 'r' in the sentence.

Ex Output:
a small bird prrchrd on a oprn window

Ex Input:
Sentence: 'several double decker buses along with other cars are traveling down a street'. Replace the letter 'b' with 'g' in the sentence.

Ex Output:
several dougle decker guses along with other cars are traveling down a street