#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  int n;
  while (cin >> n) {
    double res = 0.0;
    for (int(i) = 0; (i) < (n); (i)++) {
      int p;
      cin >> p;
      res += p;
    }
    res /= (1.0 * n);
    printf("%.10lf\n", res);
  }
}
