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

Example Input: Sentence: 'a couple of giraffe standing next to each other near  a fence'. Replace the letter 'f' with 'j' in the sentence.
Example Output: a couple oj girajje standing next to each other near  a jence

Example Input: Sentence: 'children trying little hamburgers from a tray at school'. Replace the letter 'y' with 'l' in the sentence.
Example Output: children trling little hamburgers from a tral at school

Example Input: Sentence: 'a large group of wild giraffe at a watering hole'. Replace the letter 'i' with 'c' in the sentence.
Example Output:
a large group of wcld gcraffe at a watercng hole