Xiaomei, Ou Ou and Ao Zema each bought some beef jerky. Ao Zema first gave Ou Ou (1/3) of his beef jerky, and Ou Ou gave his (1/4) beef jerky to Xiao Mei. At that time, the three of them had the same amount of beef jerky. It is known that Xiaomei originally had 12 kilograms of beef jerky. So, how many kilograms of beef jerky does Oou have?
小美、欧欧和奥斑马各买了一些牛肉干，奥斑马先将自己(1/3)的牛肉干给欧欧，欧欧又将自己(1/4)的牛肉干给小美，这时他们三人的牛肉干一样多，已知小美原来有牛肉干12千克．那么，原来欧欧有牛肉干多少千克．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">12 / (1/2)</gadget>
<output>24</output>

<gadget id="calculator">24 * (1/4)</gadget>
<output>6</output>

<gadget id="calculator">12 + 6</gadget>
<output>18</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">18 / (2/3)</gadget>
<output>27</output>

<gadget id="calculator">27 * (1/3)</gadget>
<output>9</output>

<gadget id="calculator">24 - 9</gadget>
<output>15</output>

<result>15</result>