TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a small bird perched on a open window'. Replace the letter 'e' with 'r' in the sentence.

SOLUTION: a small bird prrchrd on a oprn window

PROBLEM: Sentence: 'a refrigerator with both its doors open in a kitchen'. Replace the letter 'o' with 'x' in the sentence.

SOLUTION: a refrigeratxr with bxth its dxxrs xpen in a kitchen

PROBLEM: Sentence: 'a group of people are guiding kites on a beach'. Replace the letter 'e' with 'b' in the sentence.

SOLUTION:
a group of pboplb arb guiding kitbs on a bbach