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

namespace ConsoleApplication26
{
    class Program
    {
        static void Main(string[] args)
        {
            string usrString = Console.ReadLine();
            string tempString = "";

            foreach (char i in usrString)
            {
                if (char.IsLetter(i))
                {
                    if (char.IsLower(i))
                        tempString += char.ToUpper(i);
                    else
                        tempString += char.ToLower(i);
                }
            }
            Console.WriteLine(tempString);
            Console.ReadLine();
        }
    }
}