#include <bits/stdc++.h>
using namespace std;
int main(int argc, char* argv[]) {
  int n;
  cin >> n;
  int sum = 0;
  for (int i = 0; i < n; i++) {
    int val;
    cin >> val;
    sum += val;
  }
  printf("%.10f\n", sum / (double)n);
}
