Type the names of two bordering landlocked countries in either order to make their border appear on the map. Answers are listed in increasing order of length, measured in km.
WOW! Very fun and challenging :) Although would be better if all the other borders were given initially, but I realise that's impractical as the name of the border wouldn't appear.
I actually did it this way out of laziness, as I would have to edit the .svg to distinguish between borders that are answers and borders that aren't :D
thanks for your comment!