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

namespace yukicoder_163
{
    class Program
    {
        static void Main(string[] args)
        {
            char[]s = Console.ReadLine().ToCharArray();
            for(int i = 0; i < s.Length; i++)
            {
                if (char.IsUpper(s[i]))
                {
                    s[i] = char.ToLower(s[i]);
                }
                else
                {
                    s[i] = char.ToUpper(s[i]);
                }
            }
            string str = new string(s);
            Console.WriteLine(s);
            Console.ReadLine();
        }
    }
}