TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a horse in a country field with woods in the background'. Replace the letter 'a' with 'i' in the sentence.

SOLUTION: i horse in i country field with woods in the bickground

PROBLEM: Sentence: 'people walk through a local fruit market in a city'. Replace the letter 'e' with 'n' in the sentence.

SOLUTION: pnopln walk through a local fruit marknt in a city

PROBLEM: Sentence: 'this is a boy playing a baseball game'. Replace the letter 'y' with 'z' in the sentence.

SOLUTION:
this is a boz plazing a baseball game