TASK DEFINITION: In this task, you need to replace a letter in the sentence with another given letter.
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: 'a red stop sign sitting on the side of a road'. Replace the letter 'r' with 'o' in the sentence.

SOLUTION: a oed stop sign sitting on the side of a ooad

PROBLEM: Sentence: 'a flock of different colored sheep hanging out and eating grass'. Replace the letter 'r' with 'z' in the sentence.

SOLUTION:
a flock of diffezent colozed sheep hanging out and eating gzass