using System;
class Sample
{
    public static void Main()
    {
        string str = Console.ReadLine();
        string sum = "";
        
        for(int i = 0; i < str.Length; i++)
        {
            if (char.IsUpper(str,i))
            {
                string st = (str[i].ToString()).ToLower();
                sum += st;
            }
            if (Char.IsLower(str, i))
            {
                string st = (str[i].ToString()).ToUpper();
                sum += st;
            }
        }
        Console.WriteLine(sum);
       
    }
}