TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'many street signs in front of a building while it is snowing'. Replace the letter 'r' with 'x' in the sentence.

SOLUTION: many stxeet signs in fxont of a building while it is snowing

PROBLEM: Sentence: 'a toilet that is being worked on with its  seat removed'. Replace the letter 't' with 'p' in the sentence.

SOLUTION: a poilep phap is being worked on wiph ips  seap removed

PROBLEM: Sentence: 'there is a man about to hit a baseball'. Replace the letter 'a' with 'm' in the sentence.

SOLUTION:
there is m mmn mbout to hit m bmsebmll