There are 24 birds parked on three trees. If you fly 4 birds from the first tree to the second tree, and then fly 5 birds from the second tree to the third tree, then the number of birds on the three trees is equal, and the second How many were there on the tree?
三棵树上停着24只鸟．如果从第一棵树上飞4只鸟到第二棵树上去，再从第二棵树飞5只鸟到第三树上去，那么三棵树上的小鸟的只数都相等，第二棵树上原有几只？
<gadget id="calculator">24 / 3</gadget>
<output>8</output>

<gadget id="calculator">8 - 4</gadget>
<output>4</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<result>9</result>