There were originally 46 wooden poles on a road, and the distance between each two poles was 12 meters. Now all of them need to be replaced with cement utility poles. How many concrete utility poles are needed if the distance between every two concrete utility poles is 20 meters?
一条路原有木电线杆46根，每两根之间相隔12米．现在要全部换成水泥电线杆，如果每两根水泥电线杆之间间隔20米，共需要多少根水泥电线杆？
<gadget id="calculator">46 - 1</gadget>
<output>45</output>

<gadget id="calculator">45 * 12</gadget>
<output>540</output>

<gadget id="calculator">540 / 20</gadget>
<output>27</output>

<gadget id="calculator">27 + 1</gadget>
<output>28</output>

<result>28</result>