Arrays-LettersOfTheAlphabet

using System;

class LettersOfTheAlphabet
{
    static void Main()
    {
        char[] smallArray = new char[] { 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'v', 'x', 'y', 'z' };
        char[] largeArray = new char[] { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'V', 'X', 'Y', 'Z' };

        string input = Console.ReadLine();

        for (int i = 0; i < input.Length; i++)
        {
            for (int k = 0; k < largeArray.Length; k++)
            {
                if (input[i] == largeArray[k])
                {
                    Console.WriteLine("The letter: {0} is in position: {1}",input[i], k);
                }
                if (input[i] != largeArray[k])
                {
                    if (input[i] == smallArray[k])
                    {
                        Console.WriteLine("The letter: {0} is in position: {1}", input[i], k);
                    }
                    if (input[i] != smallArray[k])
                    {
                        Console.WriteLine("{0} is not a letter !!!",input[i]);
                        break;
                    }
                }
            }
        }
    }
}