Name each country, but the name submits when it's unique.
Ex. A country called "United" would submit as normal, as it isn't unique even at it's end, but a nation called "Xunited" would stop at X because that's where it becomes unique.
(Most) Type-ins don't work, so don't use things like UK, NZ, etc.
The two Congos use their full names for this quiz.