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

Input: Consider Input: Sentence: 'a couple of kids are sitting in a field'. Replace the letter 't' with 'v' in the sentence.

Output: a couple of kids are sivving in a field

Input: Consider Input: Sentence: 'a giraffe and a zebra stare at each other'. Replace the letter 'g' with 'l' in the sentence.

Output: a liraffe and a zebra stare at each other

Input: Consider Input: Sentence: 'two men standing in front of a white monster truck'. Replace the letter 's' with 'd' in the sentence.
Output: two men dtanding in front of a white mondter truck