Compute $121_3+2122_3-1200_3-2111_3$. Express your answer in base 3.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Compute $121_3+2122_3-1200_3-2111_3$. Express your answer in base 3.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
-221_3
Compute $121_3+2122_3-1200_3-2111_3$. Express your answer in base 3.
train