Question: What country in North America has the country calling code of 502?
Answer(s):
answer: Guatemala

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.059g4)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.059g4 ns:base.locations.continents.countries_within ?x .
?x ns:location.country.calling_code "502" . 
}