#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, k;
  cin >> n;
  double sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> k;
    sum += k / 100.0;
  }
  printf("%.12f\n", sum / n * 100);
  return 0;
}
