#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, con;
  cin >> n;
  con = n;
  double td = 0, sd;
  while (n) {
    cin >> sd;
    td += sd;
    n--;
  }
  std::cout << std ::fixed;
  std::cout << std ::setprecision(12);
  cout << td / con << endl;
  return 0;
}
