There are 28 sparrows on the two trees. Half of them fly away from the first tree to the second tree, and then 3 sparrows fly away from the second tree to the first tree. 6 more. How many sparrows were there on the first tree?
两棵树上共有麻雀28只，从第一棵树上飞走一半到第二棵树上，又从第二棵树上飞走3只到第一棵，这时第二棵比第一棵多6只．问最初第一棵树上有多少只麻雀？
<gadget id="calculator">28 - 3 - 3 - 6</gadget>
<output>16</output>

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

<gadget id="calculator">(1/2) - (1/2)</gadget>
<output>0</output>

<gadget id="calculator">1 + 0</gadget>
<output>1</output>

<gadget id="calculator">16 / 1</gadget>
<output>16</output>

<result>16</result>