Two boards of the same length are nailed together to form a new board with a length of 40 cm. The overlapping part in the middle is 12 cm. What is the original length of this board in cm?
把两块一样长的木板钉在一起，钉成了一块长40厘米的新木板，中间重叠部分是12厘米，这块木板原来长多少厘米．
<gadget id="calculator">40 - 12</gadget>
<output>28</output>

<gadget id="calculator">28 / 2</gadget>
<output>14</output>

<gadget id="calculator">14 + 12</gadget>
<output>26</output>

<result>26</result>