2
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
Find the remainder when $r^{13} + 1$ is divided by $r - 1$.
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
2
Find the remainder when $r^{13} + 1$ is divided by $r - 1$.
train