using System;
using System.Text;

namespace ConsoleApplication1
{
   class Program
    {
        private static void Main()
        {
            string text = Console.ReadLine();
            var kol = 0;
            for (int i = 0; i < text.Length; i++)
            {
                if (Char.IsDigit(text,i))
                {
                    kol++;
                }
            }
            Console.WriteLine(kol.ToString());
        }
    }
}