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

Example Input: Sentence: 'a silly cow licking the camera through a fence'. Replace the letter 't' with 'v' in the sentence.
Example Output: a silly cow licking vhe camera vhrough a fence

Example Input: Sentence: 'a group of people on a beach flying a kite'. Replace the letter 'p' with 'i' in the sentence.
Example Output: a groui of ieoile on a beach flying a kite

Example Input: Sentence: 'a cat is playing with a backpack strap'. Replace the letter 'k' with 'b' in the sentence.
Example Output:
a cat is playing with a bacbpacb strap