Multiply Big Number

using System;
using System.Linq;
namespace StringProcessingExercise5MultiplyBigNumber
{
    class Program
    {
        static void Main(string[] args)
        {

            //int n = 1234;
            //int firstD = n / 1000;
            //int secondD = n / 100 % 10;
            //int thirdD = n / 10 %10;
            //int fourthD = n % 10;

            //Console.WriteLine(firstD);
            //Console.WriteLine(secondD);
            //Console.WriteLine(thirdD);
            //Console.WriteLine(fourthD);
            string textN1 = Console.ReadLine();
            string result = string.Empty;
            byte number2 = byte.Parse(Console.ReadLine());
            int ostatak = 0;
            for (int i = textN1.Length-1; i >= 0; i--)
            {
                int currentNumber = int.Parse(textN1[i].ToString());
                int multi = (number2 * currentNumber) + ostatak;
                result += multi%10;
                ostatak = multi / 10;
            }
            if (ostatak != 0)
            {
                result += ostatak;
            }

            for(int i = result.Length - 1; i >= 0; i--)
            {
                Console.Write(result[i]);
            }

            Console.WriteLine();
        }
    }
}