<|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 mathematics test at Yang Village Elementary School's fourth grade, there are 15 questions. If Xiaoxi answered 11 questions correctly, Xiaofei answered 12 questions correctly, Xiaomei answered 13 questions correctly, and Xiaoyang answered 14 questions correctly, what is the minimum number of questions that all four of them answered correctly? 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
5
In a mathematics test at Yang Village Elementary School's fourth grade, there are 15 questions. If Xiaoxi answered 11 questions correctly, Xiaofei answered 12 questions correctly, Xiaomei answered 13 questions correctly, and Xiaoyang answered 14 questions correctly, what is the minimum number of questions that all four of them answered correctly?
test