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

Example Input: Sentence: 'there is a big room with furniture and items inside'. Replace the letter 'e' with 'k' in the sentence.
Example Output: thkrk is a big room with furniturk and itkms insidk

Example Input: Sentence: 'a close up of a grassy beach showing an umbrella and wind board'. Replace the letter 'a' with 'f' in the sentence.
Example Output: f close up of f grfssy befch showing fn umbrellf fnd wind bofrd

Example Input: Sentence: 'a no outlet sign, with street signs on top'. Replace the letter 'e' with 's' in the sentence.
Example Output:
a no outlst sign, with strsst signs on top