Task: Text Categorization
Input (English): Text:  The Van's RV-4 is a light homebuilt aircraft supplied in kit form. It seats two people in a tandem seating configuration with the pilot accommodated in the front seat.The Van's RV series has become the most popular kit-built aircraft in the world. The RV-4 is the second most popular RV model outsold only by the now discontinued RV-6. As of February 2010 1309 RV-4s had been completed and flown worldwide.
Output (English): 6