5000
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
What is the value of the sum $-1 + 2 - 3 + 4 - 5 + 6 - 7 +\dots+ 10,\!000$?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
5000
What is the value of the sum $-1 + 2 - 3 + 4 - 5 + 6 - 7 +\dots+ 10,\!000$?
train