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

Example Input: Sentence: 'a teddy bear dressed in denim is laying on a floor'. Replace the letter 'i' with 'd' in the sentence.
Example Output: a teddy bear dressed dn dendm ds laydng on a floor

Example Input: Sentence: 'a person is looking out of a large window'. Replace the letter 'o' with 'p' in the sentence.
Example Output: a perspn is lppking put pf a large windpw

Example Input: Sentence: 'a person sitting on a bench outside of a building'. Replace the letter 's' with 'b' in the sentence.
Example Output:
a perbon bitting on a bench outbide of a building