using System;
using System.Text;

class Program
{
    static void Main(string[] args)
    {
        var missPW = Console.ReadLine();
        var sb = new StringBuilder();
        for (int i = 0; i< missPW.Length; i++)
        {
            sb.Append(('a' <= missPW[i] && missPW[i] <= 'z') ? 
                              missPW[i].ToString().ToUpper() : 
                              missPW[i].ToString().ToLower());
        }
        Console.WriteLine(sb.ToString());
    }
}