using System;
using System.Linq;
using System.Numerics;

public static class P
{
    public static void Main()
    {
        string ns = Console.ReadLine();
        BigInteger res = 0;
        BigInteger dig = 1;
        foreach (var c in ns.Reverse())
        {
            if ((c - '0') % 2 != 0) res += dig;
            var cdig = dig;
            dig += cdig << 3;
            dig += cdig << 1;
        }
        Console.WriteLine(res.ToByteArray().Sum(x => PopCount(x)));
    }

    static int PopCount(int n) //byte
    {
        n = n - ((n >> 1) & 0b01010101);
        n = (n & 0b00110011) + ((n >> 2) & 0b00110011);
        return ((n * 0b00010001) >> 4) & 15;
    }
}