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