Plant trees equidistantly around a rectangular piece of land with a length of 120 meters and a width of 72 meters (must be planted at four vertices), the minimum number of trees to be planted.
在一块长120米，宽72米的长方形的土地的四周等距离种树(四个顶点上必须种)，最小要种多少棵．
<gadget id="calculator">120 + 72</gadget>
<output>192</output>

<gadget id="calculator">192 * 2</gadget>
<output>384</output>

<gadget id="calculator">384 / 24</gadget>
<output>16</output>

<result>16</result>