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