Program to add two 50- digit numbers in C#

BigNumberAddition

using System;

namespace BigNumberAddition
{
    class Addition
    {
        static void Main(string[] args)
        {
            int[] firstNumber = new int[50] { 
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5
                                    };

            int[] secondNumber = new int[50] { 
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5, 6, 7, 8, 9,
                                      1, 2, 3, 4, 5
                                    };

            int[] resultNumber = new int[50];
            int temp = 0;

            for (int i = firstNumber.Length - 1; i >= 0; i--)
            {
                resultNumber[i] = firstNumber[i] + secondNumber[i] + temp;

                if (resultNumber[i] > 9 && i != 0)
                {
                    temp = Convert.ToInt32(resultNumber[i].ToString().Substring(0, resultNumber[i].ToString().Length - 1));
                    resultNumber[i] = Convert.ToInt32(resultNumber[i].ToString().Remove(0, resultNumber[i].ToString().Length - 1));
                }
                else
                    temp = 0;
            }

            Console.WriteLine("First " + firstNumber.Length + " digits number: ");
            foreach (int i in firstNumber)
                Console.Write(i);

            Console.WriteLine("\n\nSecond " + secondNumber.Length + " digits number: ");
            foreach (int i in secondNumber)
                Console.Write(i);

            Console.WriteLine("\n\nResultant number after addition: ");
            foreach (int i in resultNumber)
                Console.Write(i);

            Console.ReadKey();
        }
    }
}