An 8-story building has 18 stairs on each floor. How many stairs do you need to walk from the 1st floor to the 8th floor?
一幢8层楼房，每层楼有18级楼梯，从1楼到8楼共需走多少级楼梯．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">7 * 18</gadget>
<output>126</output>

<result>126</result>