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

Example Input: Sentence: 'a little girl is sitting in a suitcase in a library'. Replace the letter 't' with 'l' in the sentence.
Example Output: a lillle girl is silling in a suilcase in a library

Example Input: Sentence: 'a boy is sitting at a dinner table with his food'. Replace the letter 't' with 'r' in the sentence.
Example Output: a boy is sirring ar a dinner rable wirh his food

Example Input: Sentence: 'a slice of pizza sitting on top of a paper plate'. Replace the letter 't' with 'j' in the sentence.
Example Output:
a slice of pizza sijjing on jop of a paper plaje