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 small plastic dish with food in it'. Replace the letter 'p' with 'g' in the sentence.
Example Output: a small glastic dish with food in it

Example Input: Sentence: 'a family on skis posing for a picture'. Replace the letter 'r' with 'w' in the sentence.
Example Output:
a family on skis posing fow a pictuwe