TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a cat sits on the floor next to a purse'. Replace the letter 'a' with 'b' in the sentence.

SOLUTION: b cbt sits on the floor next to b purse

PROBLEM: Sentence: 'a male holding a baseball bat standing on a big white star'. Replace the letter 'a' with 'i' in the sentence.

SOLUTION: i mile holding i bisebill bit stinding on i big white stir

PROBLEM: Sentence: 'a clock tower is shown with lights coming from it'. Replace the letter 'g' with 'h' in the sentence.

SOLUTION:
a clock tower is shown with lihhts cominh from it