#include <bits/stdc++.h>
using namespace std;
int main() {
  double n, i, j, x = 0;
  cin >> n;
  double y;
  for (i = 0; i < n; i++) {
    cin >> y;
    x = x + y;
  }
  double ans = x / n;
  cout << setprecision(10) << ans;
}
