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

Example Input: Sentence: 'a red hydrant is sitting on the sidewalk in the city'. Replace the letter 'n' with 'r' in the sentence.
Example Output: a red hydrart is sittirg or the sidewalk ir the city

Example Input: Sentence: 'the color theme in this kitchen is red and black'. Replace the letter 't' with 'v' in the sentence.
Example Output: vhe color vheme in vhis kivchen is red and black

Example Input: Sentence: 'a baseball player taking a swing at a ball'. Replace the letter 'n' with 'l' in the sentence.
Example Output:
a baseball player takilg a swilg at a ball