using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _2214
{
    class Program
    {
        static void Main(string[] args)
        {
            int a, b, k = 0, ac = 0, bc = 0, c, d;
            a = int.Parse(Console.ReadLine());
            b = int.Parse(Console.ReadLine());
            c = a;
            d = b;
            while ( c > 0 )
            {
                c /= 10;
                ac++;
            }
            while ( d > 0 )
            {
                d /= 10;
                bc++;
            }
            if (ac == bc)
            {
                while (a > 0 && b > 0)
                {
                    if (a % 10 == b % 10)
                    {
                        k++;
                    }
                    a /= 10;
                    b /= 10;
                }
                Console.WriteLine("DA");
                Console.WriteLine(k);

            }
            else
                Console.WriteLine("NU");
            Console.ReadKey();
        }
    }
}