#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, p, sum = 0;
  double x, y;
  cin >> n;
  y = n;
  while (n--) {
    cin >> p;
    sum += p;
  }
  x = sum / y;
  cout << fixed << setprecision(12) << x;
  return 0;
}
