Give the step-by-step reasoning process and then the final answer. Susan had a bouquet of 3 dozen roses. She gave half to her daughter, and then placed the rest in a vase. The next day, one-third of the flowers in the vase were wilted. After removing the wilted flowers, how many flowers remained in the vase?

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
Susan had a bouquet of 3 dozen roses, which is 3 * 12 = 36 flowers. She gave half, 36 / 2 = 18, to her daughter. Then she placed her 36 - 18 = 18 remaining flowers in a vase. One - third of the 18 flowers in the vase wilted, resulting in 18 / 3 = 6 wilted flowers. After removing the wilted flowers, Susan had 18 - 6 = 12 flowers remaining in the vase.
The final answer: 12.