#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  long long sum = 0;
  for (int i = 0; i < n; ++i) {
    int tmp;
    cin >> tmp;
    sum += tmp;
  }
  printf("%.7lf\n", sum * 1.0 / n);
  return 0;
}
