What is the largest three-digit multiple of 9 whose digits' sum is 18?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
What is the largest three-digit multiple of 9 whose digits' sum is 18?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
990
What is the largest three-digit multiple of 9 whose digits' sum is 18?
train