#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, j, k, l, m, n, o, p, q, r;
  double s = 0, t = 0, u = 0, v = 0;
  string a, b, c, d, e;
  cin >> n;
  int x[n];
  for (i = 0; i < n; i++) {
    cin >> x[i];
    s += x[i];
  }
  double y = s / n;
  printf("%.12lf", y);
}
