#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  int cs;
  while (cin >> cs) {
    int tot = 0, drnks = 0;
    for (int i = (0); i < (cs); i++) {
      cin >> drnks;
      tot += drnks;
    }
    double res = (tot * 1.0) / cs;
    cout << res << '\n';
  }
  return 0;
}
