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

Example Input: Sentence: 'a couple of white street signs sitting on top of a pole'. Replace the letter 'n' with 't' in the sentence.
Example Output: a couple of white street sigts sittitg ot top of a pole

Example Input: Sentence: 'a man laying stretched out on the back of a boat'. Replace the letter 'h' with 'g' in the sentence.
Example Output: a man laying stretcged out on tge back of a boat

Example Input: Sentence: 'a table with ingredients in plastic bags and milk'. Replace the letter 'i' with 'c' in the sentence.
Example Output:
a table wcth cngredcents cn plastcc bags and mclk