Countries bordering 4 Countries, one for each direction (N, E, S, W)
Find countries that have exactly 4 neighbours, one in each direction (North, East, South, West). Bearings are measured between the geographical centers of countries. A bearing between 45º and 135º corresponds to East, between 135º and 225º corresponds so South and so on.
Data from Portland State University (https://www.pdx.edu/econ/country-geography-data), for missing countries from CIA (https://www.cia.gov/library/publications/the-world-factbook/fields/2011.html)