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

Example Input: Sentence: 'a baseball player swings his bat at a pitch'. Replace the letter 's' with 'l' in the sentence.
Example Output: a baleball player lwingl hil bat at a pitch

Example Input: Sentence: 'a baseball player up to bat that just hit the ball'. Replace the letter 'r' with 'o' in the sentence.
Example Output: a baseball playeo up to bat that just hit the ball

Example Input: Sentence: 'people are relaxing on sofas in front of their laptops'. Replace the letter 'e' with 't' in the sentence.
Example Output:
ptoplt art rtlaxing on sofas in front of thtir laptops