3999
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Evaluate $2000^3-1999\cdot 2000^2-1999^2\cdot 2000+1999^3$
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
3999
Evaluate $2000^3-1999\cdot 2000^2-1999^2\cdot 2000+1999^3$
train