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

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

Example Input: Sentence: 'a seafood dish served over a bowl of white rice'. Replace the letter 'e' with 'u' in the sentence.
Example Output: a suafood dish survud ovur a bowl of whitu ricu

Example Input: Sentence: 'a bedroom with a picture hanging over the bed'. Replace the letter 'd' with 'g' in the sentence.
Example Output:
a begroom with a picture hanging over the beg