Given the task definition, example input & output, solve the new input case.
In this task, you need to replace a letter in the sentence with another given letter.
Example: Sentence: 'group of motorcycle motorists trying to merge into traffic'. Replace the letter 'o' with 'n' in the sentence.
Output: grnup nf mntnrcycle mntnrists trying tn merge intn traffic
The letter 'o' has been replaced in the letter 'n'.

New input case for you: Sentence: 'a bedroom that has a window, bookshelf, and a bed'. Replace the letter 'a' with 'x' in the sentence.
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
x bedroom thxt hxs x window, bookshelf, xnd x bed