Xiaoqiang and Xiaogang are good friends who live in the same building. Xiaoqiang lives on the third floor, and Xiaogang lives on the sixth floor. Xiaoqiang has to walk 18 stairs to go home every day. How many stairs does Xiaogang take to go home every day?
小强和小刚是住同一幢楼的好朋友，小强住三楼，小刚住六楼，小强每天回家要走18级楼梯，小刚每天回家要走多少级楼梯．
<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">6 - 1</gadget>
<output>5</output>

<gadget id="calculator">9 * 5</gadget>
<output>45</output>

<result>45</result>