Magic exchangeable words

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

class MagicExchangeableWords
{
    static void Main(string[] args)
    {
        string input = Console.ReadLine();
        string firstWord = input.Trim().Split(' ')[0].ToLower();
        string secondWord = input.Trim().Split(' ')[1].ToLower();
        Dictionary<char, char> exchane = new Dictionary<char, char>();
        bool isEchangebale = true;
        if (firstWord.Length == secondWord.Length)
        {
            for (int i = 0; i < firstWord.Length; i++)
            {
                if (!exchane.ContainsKey(firstWord.ElementAt(i)))
                {
                    exchane[firstWord.ElementAt(i)] = secondWord.ElementAt(i);
                }
                else
                {
                    if (exchane[firstWord.ElementAt(i)] != secondWord.ElementAt(i))
                    {
                        isEchangebale = false;
                    }
                }
            }
        }
        else if (firstWord.Length > secondWord.Length)
        {
            for (int i = 0; i < secondWord.Length; i++)
            {
                if (!exchane.ContainsKey(secondWord.ElementAt(i)))
                {
                    exchane[secondWord.ElementAt(i)] = firstWord.ElementAt(i);
                }
                else
                {
                    if (exchane[secondWord.ElementAt(i)] != firstWord.ElementAt(i))
                    {
                        isEchangebale = false;
                    }
                }
            }
            for (int i = secondWord.Length; i < firstWord.Length; i++)
            {
                if (!exchane.ContainsValue(firstWord.ElementAt(i)))
                {
                    isEchangebale = false;
                }
            }
        }
        else
        {
            for (int i = 0; i < firstWord.Length; i++)
            {
                if (!exchane.ContainsKey(firstWord.ElementAt(i)))
                {
                    exchane[firstWord.ElementAt(i)] = secondWord.ElementAt(i);
                }
                else
                {
                    if (exchane[firstWord.ElementAt(i)] != secondWord.ElementAt(i))
                    {
                        isEchangebale = false;
                    }
                }
            }
            for (int i = firstWord.Length; i < secondWord.Length; i++)
            {
                if (!exchane.ContainsValue(secondWord.ElementAt(i)))
                {
                    isEchangebale = false;
                }
            }
        }
        Console.WriteLine(isEchangebale.ToString().ToLower());
    }
}