what are all of the nations?
united states (usa), italy (ita), poland (pol), finland (fin), czechoslovakia (tch), hungary (hun), soviet union (urs), south africa (rsa), argentina (arg), germany (ger), romania (rou), sweden (swe), ireland (irl), bulgaria (bul), denmark (den), france (fra), south korea (kor)
which nations won at least 5 total medals?
united states (usa), finland (fin), soviet union (urs)
of the three, which nation won zero gold medals?
soviet union (urs)