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

Example Input: Sentence: 'people watching a kite being flown with a sky background'. Replace the letter 'a' with 'b' in the sentence.
Example Output: people wbtching b kite being flown with b sky bbckground

Example Input: Sentence: 'a man who is surfing in a wave in the ocean'. Replace the letter 'a' with 'u' in the sentence.
Example Output: u mun who is surfing in u wuve in the oceun

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