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

Example Input: Sentence: 'there is a stepladder situated over a toilet'. Replace the letter 'r' with 'x' in the sentence.
Example Output: thexe is a stepladdex situated ovex a toilet

Example Input: Sentence: 'two giraffe standing in an enclosure at the zoo next to a  tree'. Replace the letter 'n' with 'g' in the sentence.
Example Output: two giraffe stagdigg ig ag egclosure at the zoo gext to a  tree

Example Input: Sentence: 'a plate with a sandwich cut in half on it'. Replace the letter 'h' with 'f' in the sentence.
Example Output:
a plate witf a sandwicf cut in falf on it