On one side of a road, there are 31 poles at intervals of 22 meters. How many meters is this road?
一条公路的一侧每隔22米架一根电线杆，从头到尾共有31根，这条路有多少米．
<gadget id="calculator">31 - 1</gadget>
<output>30</output>

<gadget id="calculator">30 * 22</gadget>
<output>660</output>

<result>660</result>