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

Example Input: Sentence: 'a man in black shirt laying on bed with a teddy bear'. Replace the letter 'd' with 'b' in the sentence.
Example Output: a man in black shirt laying on beb with a tebby bear

Example Input: Sentence: 'a bunch of signs on a pole on the street'. Replace the letter 'c' with 's' in the sentence.
Example Output: a bunsh of signs on a pole on the street

Example Input: Sentence: 'a group of people that are holding wine glasses'. Replace the letter 'e' with 'k' in the sentence.
Example Output:
a group of pkoplk that ark holding wink glassks