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

namespace TestConsole
{
    class Program
    {
        static void Main(string[] args)
        {
            var input = Console.ReadLine();
            Console.WriteLine(input.Select(i => Char.IsUpper(i) ? Char.ToLower(i) : Char.ToUpper(i)).ToArray());
        }
    }
}