using System;
using System.Text;

class Program
{
    static void Main(string[] args)
    {
        var inputString = Console.ReadLine();
        var inputArray = inputString.ToCharArray();
        var outputString = new StringBuilder();
        foreach (var c in inputArray)
        {
            if (char.IsUpper(c))
            {
                outputString.Append(c.ToString().ToLower());
            }
            else
            {
                outputString.Append(c.ToString().ToUpper());
            }
        }
        Console.WriteLine(outputString.ToString());
    }
}