What is $1 + 2 + 3 + \cdots + 98 + 99 + 100$?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
What is $1 + 2 + 3 + \cdots + 98 + 99 + 100$?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
5050
What is $1 + 2 + 3 + \cdots + 98 + 99 + 100$?
train