#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, n, p;
  double t = 0, y, x;
  cin >> n;
  for (i = 0; i < n; i++) {
    cin >> p;
    t = t + (p / 100.00);
  }
  x = (t / n);
  y = x * 100;
  printf("%0.12lf\n", y);
  return 0;
}
