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

Example Input: Sentence: 'a man is standing on a snowboard, atop a mountain'. Replace the letter 'd' with 'u' in the sentence.
Example Output: a man is stanuing on a snowboaru, atop a mountain

Example Input: Sentence: 'a man eats food that is inside a banana peel'. Replace the letter 'n' with 'k' in the sentence.
Example Output: a mak eats food that is ikside a bakaka peel

Example Input: Sentence: 'a kitchen with stainless steel appliances and several guys'. Replace the letter 'n' with 'y' in the sentence.
Example Output:
a kitchey with staiyless steel appliayces ayd several guys