using System;

class Q0163
{
	public static void Main()
	{
		string s = Console.ReadLine();

		char[] array = s.ToCharArray();
		for (int i=0; i<array.Length; i++)
		{
			if(char.IsUpper(array[i]))
			{
				array[i] = char.ToLower(array[i]);
			}
			else if(char.IsLower(array[i]))
			{
				array[i] = char.ToUpper(array[i]);
			}
		}

		Console.WriteLine(new string(array));
	}
}