<|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
 In a city, there are 10 streets parallel to each other and 10 others intersecting them at right angles. What is the minimum number of turns required for a closed route that passes through all intersections? 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
20
In a city, there are 10 streets parallel to each other and 10 others intersecting them at right angles. What is the minimum number of turns required for a closed route that passes through all intersections?
test