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

Example Input: Sentence: 'someone playing frisbee with a dog in the middle of a court'. Replace the letter 'd' with 'r' in the sentence.
Example Output: someone playing frisbee with a rog in the mirrle of a court

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: 'large tree with wooden picnic bench in wilderness area'. Replace the letter 't' with 'x' in the sentence.
Example Output:
large xree wixh wooden picnic bench in wilderness area