using System;

class Program
{
    static void Main()
    {
        string s = Console.ReadLine();

        for(int i = 0; i < s.Length; i++)
        {
            if (Char.IsUpper(s[i]))
            {
                Console.Write(Char.ToLower(s[i]));
            }
            else
            {
                Console.Write(char.ToUpper(s[i]));
            }
        }

        Console.WriteLine();
    }
}