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

Example Input: Sentence: 'many street signs in front of a building while it is snowing'. Replace the letter 'r' with 'x' in the sentence.
Example Output: many stxeet signs in fxont of a building while it is snowing

Example Input: Sentence: 'a study features the color green and old-fashioned furniture'. Replace the letter 'e' with 'd' in the sentence.
Example Output: a study fdaturds thd color grddn and old-fashiondd furniturd

Example Input: Sentence: 'a man kneels while playing a video game with a child'. Replace the letter 'c' with 'o' in the sentence.
Example Output:
a man kneels while playing a video game with a ohild