#include <bits/stdc++.h>
using namespace std;
int main() {
  int t;
  int a;
  cin >> t;
  int p = t;
  int s = 0;
  while (t--) {
    cin >> a;
    s = s + a;
  }
  double b, c;
  b = double(s) / p;
  cout << setprecision(8) << b;
}
