using System;

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