After the introduction of high-quality rice seeds in a piece of land planted by Xiaogang's family, the rice output last year was exactly twice that of the previous year. The rice output of the year before last was 427 kilograms. How many kilograms was the rice output last year?
小刚家种的一块地引进优良稻种后，去年的水稻产量正好是前年的2倍．前年水稻产量是427千克，去年水稻产量是多少千克？
<gadget id="calculator">427 * 2</gadget>
<output>854</output>

<result>854</result>