In 2015, Greenfield produced 30 kilos of rice and 40 kilos of meat, with a kilo of rice priced at $10 and a kilo of meat at $5. In 2016, the production changed to 20 kilos of rice and 50 kilos of meat, with new prices of $7 per kilo of rice and $8 per kilo of meat. Using 2015 prices, the estimated potential GDP for 2016 is $530. What is the output gap in 2016