import java.util.Scanner;
public class Main{
    public static void main(String[] args) {
	  // TODO Auto-generated method stub
	  Scanner in = new Scanner(System.in);
	  String nn = in.next();
	  //十六进制转十进制
	  long m = Long.valueOf(nn,16);
	  System.out.println(m);
   }
}