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 Big Wood River is a 137-mile-long (220 km) river in central Idaho. It is a tributary of the Malad River which in turn is tributary to the Snake River and Columbia River.

8