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

Example Input: Sentence: 'a toddler on skis being held up by a grownup'. Replace the letter 'o' with 'k' in the sentence.
Example Output: a tkddler kn skis being held up by a grkwnup

Example Input: Sentence: 'broccoli and cooked meat arranged on a plate'. Replace the letter 'c' with 'l' in the sentence.
Example Output: brolloli and looked meat arranged on a plate

Example Input: Sentence: 'birds are on the shore of the ocean and under a bench'. Replace the letter 'r' with 'a' in the sentence.
Example Output:
biads aae on the shoae of the ocean and undea a bench