using System;

namespace SampleAppCSharp
{
    class Program
    {
        static void Main(string[] args)
        {
            string S = Console.ReadLine();

            foreach (char caps in S)
            {
                if (char.IsUpper(caps))
                    Console.Write(caps.ToString().ToLower());
                else if(char.IsLower(caps))
                    Console.Write(caps.ToString().ToUpper());
            }
            Console.WriteLine();
        }
    }
}