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

Ex Input:
Sentence: 'a broken suitcase on a small tile floor with the contents exposed'. Replace the letter 'u' with 'z' in the sentence.

Ex Output:
a broken szitcase on a small tile floor with the contents exposed


Ex Input:
Sentence: 'a table full of various types of cellphones, pdas and pagers'. Replace the letter 's' with 'f' in the sentence.

Ex Output:
a table full of variouf typef of cellphonef, pdaf and pagerf


Ex Input:
Sentence: 'a clock tower with roman numerals and a wind indicator'. Replace the letter 'n' with 'f' in the sentence.

Ex Output:

a clock tower with romaf fumerals afd a wifd ifdicator