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 Avia BH-23 was a prototype night fighter aircraft built in Czechoslovakia in 1926. The design was derived from the BH-21 day fighter incorporating the structural changes made in the BH-22 trainer and the type was originally designated BH-22N. Searchlights and other night-flying equipment were added but the Czechoslovak Air Force were not interested in the project and no sale resulted.

6