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

Example Input: Sentence: 'a woman is playing tennis on the tennis court'. Replace the letter 'r' with 'z' in the sentence.
Example Output: a woman is playing tennis on the tennis couzt

Example Input: Sentence: 'a suitcase is sitting on a sidewalk near trees'. Replace the letter 's' with 'd' in the sentence.
Example Output: a duitcade id ditting on a didewalk near treed

Example Input: Sentence: 'a group of people are flying rainbow kites in a field'. Replace the letter 'f' with 'q' in the sentence.
Example Output:
a group oq people are qlying rainbow kites in a qield