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

Example Input: Sentence: 'a man is somewhat hard to be seen in the wave, on his board'. Replace the letter 's' with 'b' in the sentence.
Example Output: a man ib bomewhat hard to be been in the wave, on hib board

Example Input: Sentence: 'a seafood dish served over a bowl of white rice'. Replace the letter 'e' with 'u' in the sentence.
Example Output: a suafood dish survud ovur a bowl of whitu ricu

Example Input: Sentence: 'a black man is smoking a cigarette outside a shop'. Replace the letter 'm' with 'p' in the sentence.
Example Output:
a black pan is spoking a cigarette outside a shop