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

Example Input: Sentence: 'a couple of giraffes eat some food out of a trey'. Replace the letter 'f' with 'e' in the sentence.
Example Output: a couple oe giraeees eat some eood out oe a trey

Example Input: Sentence: 'a horse in a country field with woods in the background'. Replace the letter 'a' with 'i' in the sentence.
Example Output: i horse in i country field with woods in the bickground

Example Input: Sentence: 'a person brushing their hair with a zac efron brush'. Replace the letter 's' with 'j' in the sentence.
Example Output:
a perjon brujhing their hair with a zac efron brujh