Definition: 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.
Input: Text:  The Type 61 Salisbury class were a class of four British aircraft direction (AD) (or radar picket) frigates built for the Royal Navy.These ships were related to the Type 41 Leopard class frigates but with reduced armament (one twin 4.5 inch mount vice two) to make way for more aircraft direction equipment particularly the four-ton radar antenna of the Type 965 (AKE-2).

6