The area of Shanghai is 5,800 square kilometers, which is 12,000 square kilometers smaller than that of Beijing. What is the area of Beijing in square kilometers?
上海市的面积5800平方千米，比北京市小12000平方千米．北京市的面积是多少平方千米？
<gadget id="calculator">5_800 + 12_000</gadget>
<output>17_800</output>

<result>17_800</result>