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

namespace ConsoleApp19
{
    class Program
    {
        static void Main(string[] args)
        {
            string s = Console.ReadLine();
            string[] password = new string[s.Length];
            for (int i = 0; i < s.Length; i++)
            {        
                if (password[i].CompareTo(password[i].ToUpper()) != 0)
                {
                    password[i] = password[i].ToUpper();
                }
                else
                {
                    password[i] = password[i].ToLower();
                }
                Console.Write(password[i]);
            }
            Console.ReadLine();
        }
    }
}