bookshelf is divided into upper, middle and lower floors, with a total of 384 books. If you take out as many books from the upper layer as the middle layer and put them in the middle layer, then take out as many books as the lower layer from the middle layer and put them in the lower layer, and finally take out as many books from the lower layer as the upper layer and put them in the upper layer, then the books in the three-layer bookshelf The original numbers are equal. How many books were there in the middle shelf?
一个书架分上中下三层，一共放书384本．如果从上层取出与中层一样多的本数放入中层，再从中层取出与下层一样多的本数放入下层，最后从下层取出与上层现在一样多的本数放入上层，这时三层书架中书的本数相等．书架的中层原来有书多少本？
<gadget id="calculator">384 / 3</gadget>
<output>128</output>

<gadget id="calculator">128 / 2</gadget>
<output>64</output>

<gadget id="calculator">128 + 64</gadget>
<output>192</output>

<gadget id="calculator">192 / 2</gadget>
<output>96</output>

<gadget id="calculator">128 + 96</gadget>
<output>224</output>

<gadget id="calculator">224 / 2</gadget>
<output>112</output>

<result>112</result>