#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int c = n;
  int sum = 0;
  while (n--) {
    int v;
    cin >> v;
    sum += v;
  }
  double rs = (double)sum / c;
  printf("%0.12lf\n", rs);
  return 0;
}
