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

Example Input: Sentence: 'a street side tree is filled with candles, teddy bears and balloons'. Replace the letter 'e' with 'c' in the sentence.
Example Output: a strcct sidc trcc is fillcd with candlcs, tcddy bcars and balloons

Example Input: Sentence: 'a white plate topped with meat and greens'. Replace the letter 's' with 'b' in the sentence.
Example Output: a white plate topped with meat and greenb

Example Input: Sentence: 'a red bull is grazing in a pasture'. Replace the letter 'i' with 'x' in the sentence.
Example Output:
a red bull xs grazxng xn a pasture