There are two boxes of goods, and box A is 18 tons more than box B. If 12 tons are taken out from box B and put into box A, the goods in box A are twice as much as box B. How many tons are the original goods in box A?
有两箱货物，甲箱比乙箱多18吨，如果从乙箱拿出12吨放入甲箱，则甲箱货物是乙箱的2倍，甲箱原有货物多少吨？
<gadget id="calculator">2 * 30</gadget>
<output>60</output>

<gadget id="calculator">60 + 12</gadget>
<output>72</output>

<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">72 / 1</gadget>
<output>72</output>

<result>72</result>