<|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 heptagon (seven-sided polygon) has all its interior angles less than 180 degrees. What is the minimum number of obtuse angles it must have? Express your answer as a whole number. 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
4
A heptagon (seven-sided polygon) has all its interior angles less than 180 degrees. What is the minimum number of obtuse angles it must have? Express your answer as a whole number.
test