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

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: 'a photo of a woman milking a brown cow'. Replace the letter 'k' with 'q' in the sentence.
Example Output: a photo of a woman milqing a brown cow

Example Input: Sentence: 'dog holds frisbee in mouth in the snow'. Replace the letter 'd' with 'n' in the sentence.
Example Output:
nog holns frisbee in mouth in the snow