#include <bits/stdc++.h>
using namespace std;
int n, tp;
double ans;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> tp;
    ans += tp;
  }
  ans = ans / n;
  cout << fixed << setprecision(12) << ans << "\n";
  return 0;
}
