There are several baskets of apples in the fruit wholesale station. Half of the apples are sold on the first day, 200 baskets are shipped on the second day, half of the existing apples are sold on the third day and 20 baskets are left, and there are still 200 baskets left. This wholesale station used to be How many baskets of apples?
水果批发站有苹果若干筐，第一天卖出苹果的一半，第二天运进200筐，第三天又卖出现有苹果的一半又20筐，结果还剩200筐，这个批发站原有苹果多少筐．
<gadget id="calculator">200 + 20</gadget>
<output>220</output>

<gadget id="calculator">220 * 2</gadget>
<output>440</output>

<gadget id="calculator">440 - 200</gadget>
<output>240</output>

<gadget id="calculator">240 * 2</gadget>
<output>480</output>

<result>480</result>