There are 19 yellow balloons in the store, 7 less red balloons than yellow balloons, and twice as many flower balloons as red balloons, how many flower balloons are there?
商店有黄气球19个，红气球比黄气球少7个，花气球的个数是红气球的2倍，花气球有多少个？
<gadget id="calculator">19 - 7</gadget>
<output>12</output>

<gadget id="calculator">12 * 2</gadget>
<output>24</output>

<result>24</result>