Find $|{-324} + 243i|$.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Find $|{-324} + 243i|$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
405
Find $|{-324} + 243i|$.
train