If you know all the countries in the world, it gives you a chance at guessing the ones you don't know. My guesses based on the fact that they begin with A were Antigua, Afghanistan, Armenia.
I knew straight away it was one of the island states and thought somehow of Aruba first. Since that's not a country, I had to look only little further. Afghanistan I only got by going through all the Asian countries. Finally got there with 26 s left.