4. The 16 to 10 participants
The semi-finals are there to deduct the participants and choose the finalists. There were 16 of them in the show. They subtracted and made it 10. You can figure them out very easily. You already know there is going to be the host country (Austria), the guest country (Australia), the usual big five; UK, Germany, Italy, France and Spain. 7 of them are already known. Now keep guessing the three of them which are left.