#include<iostream>

using namespace std;class Student{public:Student(int n,int a,float s):num(n),age(a),score(s){}void total();static float average();private:int num;int age;float score;static float sum;static int count; };

void Student::total()

{sum += score;count ++;}

float Student::average()

{return(sum/count);}

float Student::sum = 0;

int Student::count = 0;

int main()

{Student stud[3] = { Student(1001,18,70),Student(1002,19,78),Student(1005,20,98)};int n;cout<<"please input the number of students:";cin>>n;for(int i = 0;i < n;i ++){stud[i].total();}cout<<"the average score of"<<n<<"student is"<<Student::average()<<endl;return 0;}