using System;

public class Program

{

    public static void Main()

    {

        string palabra;

        Console.WriteLine("ingrese la palabra ");

        palabra = Console.ReadLine();

        for (int i = 0 ; i < palabra.Length;i++){

            if (palabra[i] >= 'A' && palabra[i] <= 'Z')

                Console.Write( Char.ToUpper(palabra[i]) );

            else if (palabra[i] >= 'a' && palabra[i] <= 'z')

                    Console.Write( Char.ToLower(palabra[i]) );

        }

        Console.ReadKey();

    }

}