class Program
    {
        static void Main(string[] args)
        {
            string inputPass = Console.ReadLine();
            string nowPass = "";
            for(int i = 0; i < inputPass.Length; i++)
            {
                if (char.IsUpper(inputPass,i))
                {
                    nowPass += inputPass[i].ToString().ToLower();
                }
                else
                {
                    nowPass += inputPass[i].ToString().ToUpper();
                }
            }
            Console.WriteLine(nowPass);
        }
    }