Index of letters

using System;
using System.Linq;

namespace Index_of_Letters
{
    class Array
    {
        static void Main(string[] args)
        {
            string str = Console.ReadLine();
            int n = 31;

            for (int i = 0; i < str.Length; i++)
            {
                int result = (str[i] & n) - 1;
                Console.WriteLine( str[i] + " -> " + result);
            }
        }
    }
}