#include<iostream>
#include<iomanip>
using namespace std;
int main(){
    int s;
    double cnt,a;
    cin>>s;
    for(int i=1;i<=s;i++){
        cin>>a;
        cnt+=a;
    }
    cout<<fixed<<setprecision(4)<<1.0*cnt/s;
    return 0;
}