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

Example Input: Sentence: 'a woman sitting on a bench under a gazebo'. Replace the letter 's' with 'u' in the sentence.
Example Output: a woman uitting on a bench under a gazebo

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 person holding there phone up to take a picture '. Replace the letter 'h' with 'e' in the sentence.
Example Output:
a person eolding teere peone up to take a picture