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

Example Input: Sentence: 'giraffes behind a fence in the trees'. Replace the letter 'h' with 'l' in the sentence.
Example Output: giraffes belind a fence in tle trees

Example Input: Sentence: 'a baseball player holding a baseball bat during a baseball game'. Replace the letter 'a' with 'u' in the sentence.
Example Output: u busebull pluyer holding u busebull but during u busebull gume

Example Input: Sentence: 'a yellow train on one out of the two tracks going by'. Replace the letter 'n' with 'v' in the sentence.
Example Output:
a yellow traiv ov ove out of the two tracks goivg by