-4
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
The sum of two numbers is $12$ and their difference is $20$. What is the smaller number?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
-4
The sum of two numbers is $12$ and their difference is $20$. What is the smaller number?
train