After Xiaoteng took a math class, he learned a lot of different shapes, but Xiaoteng's favorite triangle is because he likes stable shapes, just like his style.
After the Xiaoxun knew it, he wanted to give a triangle as a gift to Xiaoteng. He originally planned to do one, but he was too tired. So he decided to bring some wooden sticks to Xiaoteng and let Xiaoteng make a triangle himself.
One day, Xiaoxun brought $n$ sticks to Xiaoteng. Xiaoteng wanted to try to use three of them to form a triangle, but the number is too much, Xiaoteng stunned, so he can only ask for your help.