using System;

​

public class Program

{

    public static void Main()

    {

        string input = Console.ReadLine();

        string output = "";

        foreach (char c in input)

        {

            output += Char.IsUpper(c) ? Char.ToLower(c) : Char.ToUpper(c);

        }

​

        Console.WriteLine(output);

    }

}