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

Input: Consider Input: 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.

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


Input: Consider Input: Sentence: 'a back pack and lap top sit on the kitchen counter'. Replace the letter 't' with 'k' in the sentence.

Output: a back pack and lap kop sik on khe kikchen counker


Input: Consider Input: Sentence: 'a man is eating a roll and licking his thumb'. Replace the letter 'r' with 'n' in the sentence.


Output: a man is eating a noll and licking his thumb