premise: Johnny has only visited Vatican City, Greg has only visited Uzbekistan, Nathaniel has only visited Bulgaria, Mario has only visited Namibia, Troy has only visited Haiti, Jesus has only visited Federated States of Micronesia, Johnnie has only visited Bolivia, Jay has only visited Vietnam, Sidney has only visited Bosnia & Herzegovinia, Rene has only visited Tanzania, Alfred has only visited Serbia
hypothesis: Ken didn't visit Uzbekistan