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

Example Input: Sentence: 'a pile of chopped up broccoli sits next to bottles of sauces'. Replace the letter 't' with 'y' in the sentence.
Example Output: a pile of chopped up broccoli siys nexy yo boyyles of sauces

Example Input: Sentence: 'a man on the news, watched on the television'. Replace the letter 'o' with 'z' in the sentence.
Example Output: a man zn the news, watched zn the televisizn

Example Input: Sentence: 'a small bear cub sniffs the air near the water'. Replace the letter 'r' with 'k' in the sentence.
Example Output:
a small beak cub sniffs the aik neak the watek