using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(UniqueDigits("111222"));

        Console.WriteLine(UniqueDigits("1002345"));

        Console.WriteLine(UniqueDigits("000000"));

    }

    private static int UniqueDigits(string str) => str.Where(x => char.IsDigit(x)).GroupBy(x => x).Count();

}