bamboo pole is vertically inserted into the bottom of the water. The bamboo pole is 40 cm wet. Then the bamboo pole is turned around and inserted into the water bottom. At this time, the wet part of the bamboo pole is 13 cm longer than its half.
把一根竹竿垂直插入水底，竹竿湿了40厘米，然后将竹竿转过来插入水底，这时竹竿湿的部分比它的一半长13厘米，则竹竿长多少厘米．
<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<gadget id="calculator">80 - 13</gadget>
<output>67</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">67 / (1/2)</gadget>
<output>134</output>

<result>134</result>