Good num

using System;
using System.Linq;
using System.Security.Cryptography;

namespace _05._Good_numbers
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine();
            int[] numbers = input
                .Split(' ')
                .Select(int.Parse)
                .ToArray();
            int firstNumber = numbers[0];
            int lastNummber = numbers[1];
            int counter = 0;
            bool isValid = true;

            for (int i = firstNumber; i <= lastNummber; i++)
            {

                string checkNumber=i.ToString();
                for (int j = 0; j < checkNumber.Length; j++) //deli chisloto na vsqko ot chislata
                {
                    char digit = checkNumber[j];
                    if (digit-'0' == 0)
                    {
                        if (j==checkNumber.Length-1)
                        {
                            counter++;  continue;
                        }
                        else
                        {
                            continue;
                        }
                    }
                    isValid = i % (digit - '0') == 0;

                    if (!isValid)
                    {
                        break;
                    }
                    if (isValid&&j==checkNumber.Length-1)
                    {
                        counter++;
                    }

                }
            }
            Console.WriteLine(counter);
        }
    }
}