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

Example Input: Sentence: 'a young boy riding his skateboard down the sidewalk'. Replace the letter 'd' with 'p' in the sentence.
Example Output: a young boy riping his skateboarp pown the sipewalk

Example Input: Sentence: 'plated foods displayed on table with condiments and side dishes'. Replace the letter 's' with 'd' in the sentence.
Example Output: plated foodd didplayed on table with condimentd and dide didhed

Example Input: Sentence: 'person on a motorbike riding around a track as people watch'. Replace the letter 's' with 'f' in the sentence.
Example Output:
perfon on a motorbike riding around a track af people watch