To add to Tooki's point, save yourself the cost of the expensive Apple-branded international plug adapter set and just get yourself the standard cables with figure-of-eight connectors at one end and a plug for whichever country you're travelling to at the other end. I have three permanently in my travel bag - a 3-pin for the UK, 2-pin for continental Europe and 2-pin for North America and Japan. They're extra useful as they double up as connectors for most battery rechargers, etc, so I only need to travel with one cable and no bulky adapters.
I also have about half a dozen figure-of-eight connectors in various rooms of my house so I can just plug in the Apple power block in whichever room I'm in without reaching behind wardrobes and sofas to get to the wall socket.