TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a bike sitting parked next to a cart in front of some boxes'. Replace the letter 't' with 'x' in the sentence.

SOLUTION: a bike sixxing parked nexx xo a carx in fronx of some boxes

PROBLEM: Sentence: 'it pays a cat to be suspicious of what your owner tries to feed you'. Replace the letter 'o' with 'g' in the sentence.

SOLUTION: it pays a cat tg be suspicigus gf what ygur gwner tries tg feed ygu

PROBLEM: Sentence: 'a bus parked in a bus station in front of a building'. Replace the letter 's' with 'c' in the sentence.

SOLUTION:
a buc parked in a buc ctation in front of a building