In this task, you need to replace a letter in the sentence with another given letter.

Sentence: 'four people are playing an interesting game in the park'. Replace the letter 'e' with 'x' in the sentence.
four pxoplx arx playing an intxrxsting gamx in thx park

Sentence: 'a couple of horses with carriages at a building'. Replace the letter 'u' with 'm' in the sentence.
a comple of horses with carriages at a bmilding

Sentence: 'a giraffe and a zebra stare at each other'. Replace the letter 'g' with 'l' in the sentence.

a liraffe and a zebra stare at each other