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

Example Input: Sentence: 'a man is posing in a desert, leaning on a sign with an image of a camel on it'. Replace the letter 'i' with 'r' in the sentence.
Example Output: a man rs posrng rn a desert, leanrng on a srgn wrth an rmage of a camel on rt

Example Input: Sentence: 'a black cat is sniffing a glass bottle'. Replace the letter 'c' with 'f' in the sentence.
Example Output: a blafk fat is sniffing a glass bottle

Example Input: Sentence: 'a woman is talking on her white phone'. Replace the letter 'w' with 'r' in the sentence.
Example Output:
a roman is talking on her rhite phone