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

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: 'an older red airplane is going straight up'. Replace the letter 'h' with 'z' in the sentence.

Ex Output:
an older red airplane is going straigzt up


Ex Input:
Sentence: 'a couch, coffee table, book stand, lamp and photos on the wall'. Replace the letter 'f' with 'h' in the sentence.

Ex Output:

a couch, cohhee table, book stand, lamp and photos on the wall