Congcong's classroom is on the fifth floor. There are 18 stairs on each floor. How many steps did he walk from the first floor to the fifth floor?
聪聪的教室在五楼，每层楼梯有18级，他从1楼到五楼，共走多少级．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">18 * 4</gadget>
<output>72</output>

<result>72</result>