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

Example Input: Sentence: 'a man that is on the back of an elephant'. Replace the letter 'c' with 'd' in the sentence.
Example Output: a man that is on the badk of an elephant

Example Input: Sentence: 'a baseball player running on a baseball field'. Replace the letter 'e' with 'h' in the sentence.
Example Output: a bashball playhr running on a bashball fihld

Example Input: Sentence: 'a door open to reveal a urinal and graffiti on the wall'. Replace the letter 'a' with 'f' in the sentence.
Example Output:
f door open to revefl f urinfl fnd grfffiti on the wfll