package work;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner in=new Scanner(System.in);
int a=in.nextInt();/*输入的数*/
int c=1;/*位数*/
int count=0;/*二进制值*/
do
{
int b=a%10;/*b为个位数*/
if((b%2)==(c%2))/*比较奇偶性是否相同*/
{
count=(int) (count+Math.pow(2, c-1));/*二进制值*/
}
c=c+1;
a=a/10;
}while(a!=0);
System.out.println(count);
}
}