Instructions: In this task, you need to replace a letter in the sentence with another given letter.
Input: Sentence: 'a woman is custom painting a red umbrella'. Replace the letter 't' with 'z' 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
a woman is cuszom painzing a red umbrella