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

Sentence: 'a table full of various types of cellphones, pdas and pagers'. Replace the letter 's' with 'f' in the sentence.
a table full of variouf typef of cellphonef, pdaf and pagerf

Sentence: 'a busy intersection with cars moving at night'. Replace the letter 's' with 'f' in the sentence.
a bufy interfection with carf moving at night

Sentence: 'a long train on a narrow train track'. Replace the letter 'i' with 'p' in the sentence.

a long trapn on a narrow trapn track