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

namespace template
{
    class Program
    {
        static void Main(string[] args)
        {
            char[] cs = Console.ReadLine().ToCharArray();
            for (int i = 0; i < cs.Length; i++)
            {
                if (char.IsUpper(cs[i]))
                {
                    cs[i] = char.ToLower(cs[i]);
                }
                else if (char.IsLower(cs[i]))
                {
                    cs[i] = char.ToUpper(cs[i]);
                }
            }
            string s2 = new string(cs);
            Console.WriteLine(s2);
        }
    }
}