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

Example Input: Sentence: 'a black cat is sniffing a glass bottle'. Replace the letter 'c' with 'f' in the sentence.
Example Output: a blafk fat is sniffing a glass bottle

Example Input: Sentence: 'broccoli and cooked meat arranged on a plate'. Replace the letter 'c' with 'l' in the sentence.
Example Output: brolloli and looked meat arranged on a plate

Example Input: Sentence: 'a small propeller plane sits on the runway'. Replace the letter 'a' with 'f' in the sentence.
Example Output:
f smfll propeller plfne sits on the runwfy