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 living room with an orange couch and green decorations'. Replace the letter 'c' with 'm' in the sentence.
Example Output: a living room with an orange moumh and green demorations

Example Input: Sentence: 'a safari setting at a zoo with two giraffes and a zebra'. Replace the letter 'n' with 'g' in the sentence.
Example Output:
a safari settigg at a zoo with two giraffes agd a zebra