Given the task definition and input, reply with output. In this task, you need to replace a letter in the sentence with another given letter.

Sentence: 'a trio of computer monitors on stacks of books on a desk'. Replace the letter 's' with 't' in the sentence.

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
a trio of computer monitort on ttackt of bookt on a detk