#include <bits/stdc++.h>
using namespace std;
int n;
int main() {
  cin >> n;
  int a;
  int sum = 0;
  for (int i = 1; i <= n; i++) {
    cin >> a;
    sum += a;
  }
  cout << setprecision(12) << fixed << sum * 1.0 / n;
}
