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

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

            for (int i = 0; i < S.Length; i++)
            {
                if(char.IsUpper(S,i)){
                    str += S.Substring(i, 1).ToLower();
                }
                else
                {
                    str += S.Substring(i, 1).ToUpper();
                }
            }

            Console.WriteLine(str);
        }
    }
}