The cafeteria bought a batch of rice. The first time I ate half of the rice, I lost 10 kilograms, and the second time I ate the remaining half, 10 kilograms more. At this time, there are still 20 kilograms left. How many kilograms of this batch of rice are there?
食堂买了一批大米，第一次吃了全部的一半少10千克，第二次吃了余下的一半多10千克，这时还剩20千克，这批大米共有多少千克？
<gadget id="calculator">20 + 10</gadget>
<output>30</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">60 - 10</gadget>
<output>50</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<result>100</result>