#include <iostream>
#include <cstdio>
using namespace std;
int main() {
    int n;
    long double sum=0;
    cin>>n;
    int a[n];
    for (int i = 0; i < n; ++i) {
        cin>>a[i];
    }
    for (int i = 0; i < n; ++i) {
        sum+=a[i];
    }
    printf("%.2Lf",sum/n);
}