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

Example Input: Sentence: 'there is a piece of a cake on the plate and a cup of drink'. Replace the letter 'r' with 'u' in the sentence.
Example Output: theue is a piece of a cake on the plate and a cup of duink

Example Input: Sentence: 'a house cat sits on an oven door, sniffing the oven racks inside'. Replace the letter 'i' with 'y' in the sentence.
Example Output: a house cat syts on an oven door, snyffyng the oven racks ynsyde

Example Input: Sentence: 'an older woman prepares to eat a sandwich'. Replace the letter 'h' with 'z' in the sentence.
Example Output:
an older woman prepares to eat a sandwicz