using System;
using System.Collections.Generic;

class program
{
    public static void Main()
    {
        var S = Console.ReadLine();

        var ans = "";
        foreach (var str in S)
        {
            if (char.IsUpper(str))
            {
                ans += char.ToLower(str);
            }
            else
            {
                ans += char.ToUpper(str);
            }
        }
        Console.WriteLine(ans);
    }
}