<|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 class of 45 students, all students participate in a tug-of-war. Among the remaining three events, each student participates in at least one event. It is known that 39 students participate in the shuttlecock kicking event and 28 students participate in the basketball shooting event. How many students participate in all three events? 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
22
In a class of 45 students, all students participate in a tug-of-war. Among the remaining three events, each student participates in at least one event. It is known that 39 students participate in the shuttlecock kicking event and 28 students participate in the basketball shooting event. How many students participate in all three events?
test