There used to be 29 telephone poles on one side of an old street, and the distance between each two adjacent poles was 40 meters. Now the government has decided to replace all of them with large cement utility poles, with every two adjacent poles 28 meters apart. So how many large cement poles are needed.
一条旧街道的一侧原来有电线杆29根，每相邻两根相距40米．现在政府决定全部换成大型水泥电线杆，每相邻两根相距28米．那么需大型水泥电线杆多少根．
<gadget id="calculator">29 - 1</gadget>
<output>28</output>

<gadget id="calculator">28 * 40</gadget>
<output>1_120</output>

<gadget id="calculator">1_120 / 28</gadget>
<output>40</output>

<gadget id="calculator">40 + 1</gadget>
<output>41</output>

<result>41</result>