The owner chases his dog. When the dog runs three steps, the owner runs two steps, but the owner's one step is the dog's two steps. After the dog runs 10 steps, the owner starts to chase. When the owner catches up with the dog, how many steps does the dog run ．
主人追他的狗，狗跑三步的时间主人跑两步，但主人的一步是狗的两步，狗跑出10步后，主人开始追，主人追上狗时，狗跑出了多少步．
<gadget id="calculator">2 * 2</gadget>
<output>4</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">10 / 1</gadget>
<output>10</output>

<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">30 + 10</gadget>
<output>40</output>

<result>40</result>