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

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 group of people hanging around holding umbrellas'. Replace the letter 'p' with 'f' in the sentence.
Example Output: a grouf of feofle hanging around holding umbrellas

Example Input: Sentence: 'a person feeds a kitten with a bottle'. Replace the letter 'e' with 'l' in the sentence.
Example Output:
a plrson fllds a kittln with a bottll