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

Example Input: Sentence: 'adult man on grassy field playing disc game'. Replace the letter 'n' with 'l' in the sentence.
Example Output: adult mal ol grassy field playilg disc game

Example Input: Sentence: 'a small train is on the tracks by a house'. Replace the letter 'l' with 'x' in the sentence.
Example Output: a smaxx train is on the tracks by a house

Example Input: Sentence: 'two people standing inside a large open room together'. Replace the letter 'h' with 'x' in the sentence.
Example Output:
two people standing inside a large open room togetxer