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)
        {
            char[] password = Console.ReadLine().ToCharArray();
            for (int i = 0; i < password.Length; i++)
            {
                if (char.IsUpper(password[i]))
                {
                    password[i] = char.ToLower(password[i]);
                }
                else if (char.IsLower(password[i]))
                {
                    password[i] = char.ToUpper(password[i]);
                }
            }
            string s = new string(password);
            Console.WriteLine(s);
        }
    }
}