premise: Norman has only visited Montenegro, Adam has only visited Denmark, Scott has only visited Iraq, Barry has only visited South Korea, Mike has only visited Saint Vincent & the Grenadines, Dan has only visited Benin, Javier has only visited Equatorial Guinea, Peter has only visited Yemen, Manuel has only visited Moldova, Sam has only visited Grenada, Arthur has only visited Sudan, Calvin has only visited Tonga
hypothesis: Norman didn't visit Montenegro