There is a piece of grass that can feed 8 sheep for 20 days, or feed 14 sheep for 10 days. Assuming that the growth rate of the grass remains unchanged every day, there are several sheep, and after eating for 4 days, there will be an increase of 6 sheep. After eating for another 12 days, the grass will be eaten up. How many sheep are there?
有一片草地，可供8只羊吃20天，或供14只羊吃10天．假设草每天的生长速度不变，现有羊若干只，吃了4天后又增加了6只，这样又吃了12天，便将草吃完．问原有羊几只？
<gadget id="calculator">12 + 4</gadget>
<output>16</output>

<gadget id="calculator">8 * 20</gadget>
<output>160</output>

<gadget id="calculator">14 * 10</gadget>
<output>140</output>

<gadget id="calculator">160 - 140</gadget>
<output>20</output>

<gadget id="calculator">20 - 10</gadget>
<output>10</output>

<gadget id="calculator">20 / 10</gadget>
<output>2</output>

<gadget id="calculator">16 * 2</gadget>
<output>32</output>

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

<gadget id="calculator">6 * 20</gadget>
<output>120</output>

<gadget id="calculator">12 * 6</gadget>
<output>72</output>

<gadget id="calculator">120 - 72</gadget>
<output>48</output>

<gadget id="calculator">32 + 48</gadget>
<output>80</output>

<gadget id="calculator">4 + 12</gadget>
<output>16</output>

<gadget id="calculator">80 / 16</gadget>
<output>5</output>

<result>5</result>