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

Example Input: Sentence: 'people are standing outside in the parking lot'. Replace the letter 'i' with 'z' in the sentence.
Example Output: people are standzng outszde zn the parkzng lot

Example Input: Sentence: 'a white plate topped with meat and greens'. Replace the letter 's' with 'b' in the sentence.
Example Output: a white plate topped with meat and greenb

Example Input: Sentence: 'the couple is sitting at the table talking with friends'. Replace the letter 'a' with 'w' in the sentence.
Example Output:
the couple is sitting wt the twble twlking with friends