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: 'the airplane is parked on the runway for people to look at'. Replace the letter 'a' with 'e' in the sentence.
Example Output: the eirplene is perked on the runwey for people to look et

Example Input: Sentence: 'a bride shoves wedding cake into the mouth of her husband'. Replace the letter 'i' with 'w' in the sentence.
Example Output:
a brwde shoves weddwng cake wnto the mouth of her husband