#include<iostream>
using namespace std;
Class statistics{
    double mean;
    public:
    statistics(int n, int a[]){
        int sum=0;
        for(int i=0; i<n; i++) sum +=a[i];
        mean= (double)sum/n;
    }
    statistics(const statistics &s) { mean=
    s.mean; }
    void show() { cout << mean; }
};
int main(){
    int n;
    cin>>n;
    
    if(n<o){
        cout <<"invalid input";
        return 0;
    }
    int a[10];
    for(int i=0; i <n; i++) cin >> a[i];
    statistics s1(n,a):
    statistics s2 =s1;
    s2.show();
}