#include <bits/stdc++.h>
using namespace std;
int main() {
  int i, j, k, l, m, n, a;
  double f = 0.0;
  cin >> n;
  for (i = 1; i <= n; i++) {
    cin >> a;
    f += (a / 100.0);
  }
  double h = (f * 100.0) / n;
  cout << setprecision(10) << h << endl;
}
