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

Example Input: Sentence: 'a man holds his hands out in pursuit of a disk'. Replace the letter 'n' with 'o' in the sentence.
Example Output: a mao holds his haods out io pursuit of a disk

Example Input: Sentence: 'a man taking a photo of food on a table'. Replace the letter 't' with 'h' in the sentence.
Example Output: a man haking a phoho of food on a hable

Example Input: Sentence: 'a man smiles as he looks at his cell phone'. Replace the letter 'a' with 'd' in the sentence.
Example Output:
d mdn smiles ds he looks dt his cell phone