From A to B, a telegraph pole was originally erected every 45 meters, plus 2 at both ends, a total of 53 poles, but now it is changed to erect a telegraph pole every 60 meters. Q: In addition to the two poles at the two ends that do not move, are there any poles in the middle that do not have to move? If yes, find out the number of roots that do not need to be moved; if not, please explain why.
从甲地到乙地原来每隔45米竖一根电线杆，加上两端的2根，共有53根，现在改为每隔60米竖一根电线杆．问：除了两端的两根电线杆不动外，中间是否还有电线杆不必移动？若有，求出不必移动的根数；若没有，请说明理由．
<gadget id="calculator">53 - 1</gadget>
<output>52</output>

<gadget id="calculator">45 * 52</gadget>
<output>2_340</output>

<gadget id="calculator">2_340 / 180</gadget>
<output>13</output>

<gadget id="calculator">13 - 1</gadget>
<output>12</output>

<result>12</result>