Compute $(-1 + i \sqrt{3})^8.$  Enter the answer in rectangular form.
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Compute $(-1 + i \sqrt{3})^8.$  Enter the answer in rectangular form.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
-128 - 128 \sqrt{3} i
Compute $(-1 + i \sqrt{3})^8.$  Enter the answer in rectangular form.
train