#include <bits/stdc++.h>
using namespace std;
void solve() {
  int n;
  cin >> n;
  double j = 0;
  for (int i = 1; i <= n; i++) {
    int t;
    cin >> t;
    j += t;
  }
  cout << fixed << setprecision(12) << (j / n) << endl;
}
int main() { solve(); }
