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

Example Input: Sentence: 'a man rolling dough in the kitchen'. Replace the letter 'a' with 'e' in the sentence.
Example Output: e men rolling dough in the kitchen

Example Input: Sentence: 'a blue and white train is coming down some tracks'. Replace the letter 'b' with 'u' in the sentence.
Example Output: a ulue and white train is coming down some tracks

Example Input: Sentence: 'a young girl sitting a table with a flower turned on its bloom and scissors nearby'. Replace the letter 'i' with 'z' in the sentence.
Example Output:
a young gzrl szttzng a table wzth a flower turned on zts bloom and sczssors nearby