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

Example Input: Sentence: 'bananas, oranges and apples are in shades of yellow and orange'. Replace the letter 'r' with 'b' in the sentence.
Example Output: bananas, obanges and apples abe in shades of yellow and obange

Example Input: Sentence: 'a ski slope consisting of several people wearing skis and snowboards'. Replace the letter 'e' with 's' in the sentence.
Example Output: a ski slops consisting of ssvsral psopls wsaring skis and snowboards

Example Input: Sentence: 'a crowd of people watching a woman pose on an antique glider'. Replace the letter 'a' with 'u' in the sentence.
Example Output:
u crowd of people wutching u womun pose on un untique glider