#include <bits/stdc++.h>
using namespace std;
int n, m;
int main() {
  while (cin >> n) {
    int s = 0, t;
    for (int i = 0; i < n; i++) scanf("%d", &t), s += t;
    printf("%.12lf\n", 1.0 * s / n);
  }
}
