premise: Russell has only visited Estonia, Vernon has only visited Latvia, Johnny has only visited New Zealand, Duane has only visited Sri Lanka, Virgil has only visited Zambia, Shawn has only visited Cameroon, Phillip has only visited Maldives, Sergio has only visited Djibouti, Clinton has only visited Malta, Tommy has only visited United Arab Emirates, Kirk has only visited Algeria
hypothesis: Shawn didn't visit Antigua & Barbuda