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

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

Sentence: 'a clean, sterile bathroom with a shower, toilet, and sink'. Replace the letter 'n' with 'k' in the sentence.
a cleak, sterile bathroom with a shower, toilet, akd sikk

Sentence: 'a pedestrian crossing sign sitting underneath a street sign'. Replace the letter 'e' with 'v' in the sentence.
a pvdvstrian crossing sign sitting undvrnvath a strvvt sign