#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  unsigned long long c = 0;
  int p;
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> p;
    c += p;
  }
  cout << setprecision(14) << ((double)c / n);
}
