#include<stdio.h>
 
int main()
{
    int nonnegative_number;
    int a,b=0,f;//a：输入数每位的存储单元。b：位数。f：存储2为多少次幂（二进制位）
    int c,d=0;//c：如果满足题意  奇偶相同为1，否则为零。d：储存结果，
    scanf("%d",&nonnegative_number);
    while(nonnegative_number != 0)
    {
        a = nonnegative_number%10;
        b++;
        f = b;
        if(a == 0)
        {
            c = 0;
        }
        else if(a%2 == b%2)
        {
            c = 1;
            for(f;f>1;f--)
            {
                c = c*2;
            }
        }
        else
        {
            c = 0;
        }
        d += c;
        nonnegative_number = nonnegative_number/10;
    }
    printf("%d",d);
    return 0;
}