using System;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
class Program
{
    static void Main()
    {
        string characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        string result = "";
        string s = Console.ReadLine();
        for(int X = 0; X < s.Length; X++)
        {
            if (characters.Contains(s[X]) == true)
            {
                result += s[X].ToString().ToLower();
            }
            else
            {
                result += s[X].ToString().ToUpper();
            }
        }
        Console.WriteLine(result);
    }
}