using System;

public class Test
{
	public static void Main()
	{
		var s = Console.ReadLine();
		
		string str = "";
		
		foreach(char c in s)
		{
			if(char.IsUpper(c)) str+= char.ToLower(c);
			else str += char.ToUpper(c);
		}
		
		Console.WriteLine(str);
	}
}