<|im_start|>system
You are a helpful assistant. You first think about the reasoning process in the mind and then provide the user with the answer. You should try to truely solve the question by yourself without cheating.  <|im_end|>
<|im_start|>user
 A son is 4 times younger than his dad. The difference in their ages is 27. How old is the dad if the son is 9 years old? Show your work in <think> </think> tags. And return the final answer in <answer> </answer> tags.<|im_end|>
<|im_start|>assistant
Let me solve this step by step.
<think>
user
63
A son is 4 times younger than his dad. The difference in their ages is 27. How old is the dad if the son is 9 years old?
test