Suppose that Hungary and Liechtenstein both produce ale and glass. Hungary's opportunity cost of producing a pane of glass is 6 kegs of ale while Liechtenstein's opportunity cost of producing a pane of glass is 11 kegs of ale. By comparing the opportunity cost of producing glass in the two countries, you can tell that has a comparative advantage in the production of glass and has a comparative advantage in the production of ale. Suppose that Hungary and Liechtenstein consider trading glass and ale with each other. Hungary can gain from specialization and trade as long as it receives more than of ale for each pane of glass it exports to Liechtenstein. Similarly, Liechtenstein can gain from trade as long as it receives more than of glass for each keg of ale it exports to Hungary.