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

Example Input: Sentence: 'a patio filled with white tables and chairs covered with umbrellas'. Replace the letter 'o' with 'e' in the sentence.
Example Output: a patie filled with white tables and chairs cevered with umbrellas

Example Input: Sentence: 'commuter trains on tracks next to paved platform'. Replace the letter 'm' with 'w' in the sentence.
Example Output: cowwuter trains on tracks next to paved platforw

Example Input: Sentence: 'two dogs lounge on a chair that is seated by a window'. Replace the letter 'd' with 'w' in the sentence.
Example Output:
two wogs lounge on a chair that is seatew by a winwow