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

Example Input: Sentence: 'a clock mounted above a door entrance with windows'. Replace the letter 's' with 'l' in the sentence.
Example Output: a clock mounted above a door entrance with windowl

Example Input: Sentence: 'street signs hanging next to a traffic light on a city street'. Replace the letter 'g' with 'm' in the sentence.
Example Output: street simns hanminm next to a traffic limht on a city street

Example Input: Sentence: 'skiers standing on a ski slope in the snow'. Replace the letter 'a' with 'n' in the sentence.
Example Output:
skiers stnnding on n ski slope in the snow