using System;

class Program
{
    static void Main(string[] args)
    {
        string s = Console.ReadLine();
        string output = "";

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

        Console.WriteLine(output);
    }
}