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

Example Input: Sentence: 'a pink table topped with plates and bowls of food'. Replace the letter 'p' with 'x' in the sentence.
Example Output: a xink table toxxed with xlates and bowls of food

Example Input: Sentence: 'a man on a surfboard riding on the waters waves'. Replace the letter 's' with 'k' in the sentence.
Example Output: a man on a kurfboard riding on the waterk wavek

Example Input: Sentence: 'a girl sitting in a chair eating a slice of pizza'. Replace the letter 'i' with 'x' in the sentence.
Example Output:
a gxrl sxttxng xn a chaxr eatxng a slxce of pxzza