In this task, you are given a text which is the body of a document. Your job is to classify the topic of the document into these categories: 1)Company, 2)Educational Institution, 3)Artist, 4)Athlete, 5)Office Holder, 6)Mean of transportation, 7)Building, 8)Natural place, 9)Village, 10)Animal, 11)Plant, 12)Album, 13)Film, 14)Written work. Your output should be the category number. Don't generate anything apart from numbers 1-14.

Text: The Chien Lung class of submarine was manufactured in the Netherlands for the Republic of China (Taiwan) and is currently in service with its navy. They are a modified version of the Dutch Navy's Zwaardvis class submarine which is based on the US Barbel Class.
6