Xiao Ming has to walk 16 steps from the first floor to the second floor. How many steps does he need to walk from the second floor to the fourth floor?
小明从一楼到二楼要走16个台阶，他从二楼走到四楼需要走多少个台阶．
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">16 / 1</gadget>
<output>16</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

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

<result>32</result>