TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a person that is sitting under an umbrella'. Replace the letter 'a' with 'l' in the sentence.

SOLUTION: l person thlt is sitting under ln umbrelll

PROBLEM: Sentence: 'a couple of giraffe standing next to each other'. Replace the letter 't' with 'c' in the sentence.

SOLUTION: a couple of giraffe scanding nexc co each ocher

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