There are two kinds of candies in the candy store, butterscotch and fruit candy. The kilogram of butterscotch is twice that of fruit candy. These candies are ready to be boxed. If each box of candy needs 8 kg of butterscotch and 3 kg of fruit sugar, then in the end there will be a shortage of 4 kg of butterscotch and 4 kg of fruit sugar. How many boxes of candy are there, please?
糖果店有奶油糖和水果糖两种糖果，奶油糖千克数是水果糖的2倍，准备把这些糖果装箱．如果每箱糖果需要奶油糖8千克，水果糖3千克，那么最后奶油糖缺4千克，水果糖剩4千克．请问装了多少箱糖果？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">4 + 8</gadget>
<output>12</output>

<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">8 - 6</gadget>
<output>2</output>

<gadget id="calculator">12 / 2</gadget>
<output>6</output>

<result>6</result>