Start by naming any country that France borders. Then name any country that borders any of those countries. Then keep going until there are no more countries left to name.
This is a fantastic quiz! You did a really, really good job on it! I got some that I never thought I could (like Pal Meraktis) but I missed so easy ones like Nayna and Godot. I would accept both first and last names if I made this quiz. I understand why you didn’t, though. First of all it would take a ton of time, and secondly some names that people might not get (like Ami Fey) could be guessed with just Fey (which tons of people would get with Maya). Anyway, amazing job here!