In an elementary school teaching building, there are 20 steps between two adjacent floors. How many steps do you need to climb from the first floor to the fifth floor?
小学教学楼，相邻两层之间都有20级台阶，从一楼到五楼，一共要爬多少级台阶．
<gadget id="calculator">5 - 1</gadget>
<output>4</output>

<gadget id="calculator">20 * 4</gadget>
<output>80</output>

<result>80</result>