TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
PROBLEM: Sentence: 'a group of small children sitting at a table in front of a pizza'. Replace the letter 'r' with 'd' in the sentence.

SOLUTION: a gdoup of small childden sitting at a table in fdont of a pizza

PROBLEM: Sentence: 'a tower type building structure with a large clock and many windows in front of a cloudy blue sky'. Replace the letter 'n' with 'x' in the sentence.

SOLUTION: a tower type buildixg structure with a large clock axd maxy wixdows ix froxt of a cloudy blue sky

PROBLEM: Sentence: 'two zebras walking in a sandy area outside'. Replace the letter 'a' with 'p' in the sentence.

SOLUTION:
two zebrps wplking in p spndy prep outside