#include<iostream>
using namespace std;
class Statistics{
    double mean;
public:
    Statistics(int a [],int n){
        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<0){
        cout<<"Invalid input";
        return 0;
    }
    int a[n];
    for(int i=0;i<n;i++)cin>>a[i];
    Statistics s1(a,n);
    Statistics s2=s1;
    s2.show();