Task: Text Categorization
Input (English): Context: Bikin (Russian: Бики́н) is a river in Primorsky and Khabarovsk Krais in Russia. It is a right tributary of the Ussuri River and is 560 km long with a drainage basin of 22 300 km².Main tributaries are the Alchan Bachelaza and Zeva Rivers.The town Bikin is situated at the Bikin River.
Question: The document can be classified to which topic? 
Options: 1)Building, 2)Plant, 3)NaturalPlace, 4)Artist
Output (English): 3