#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n;
  vector<int> a(n + 2);
  double count = 0, count1 = 0;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    count += a[i];
  }
  cout << count / n;
}
