using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            var input = Convert.ToString('a', 2);
            var key = Convert.ToString('b', 2);
            int result = 0;

            for (int i = 0; i < input.Length; i++)
            {
                result += (int) Math.Pow(input[i] != key[i] ? 1 : 0, i);
            }

            Console.WriteLine("{1} xor {2} = {3} = {1}", Convert.ToChar(result), input, key, result);
        }
    }
}