A country is landlocked because its surrounded by other countries, so it would be just logical if every country would border a landlocked country. But this is still quite often not the case, because of several political or historical factors. Guess where this isn’t the case.
No borderless countries
And no landlocked countries itself like San Marino (they would work, but absolutely dont fit in this category)
Evil aliens have decided to kill everyone on Earth! Fortunately, they've given you two minutes to save as many as you can. All you have to do is name a country to save everyone in it.