5
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
If $a + b = c$ and $b + c = 11$ and $c = 8$, what is the value of $a$?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
5
If $a + b = c$ and $b + c = 11$ and $c = 8$, what is the value of $a$?
train