Definition: The operation symbol "*" satisfies 2*3=2+3+4=9, 3*4=3+4+5+6=18, then 2*5=how much.
定义：运算符号"*"满足2*3=2+3+4=9，3*4=3+4+5+6=18，则2*5=多少．
<gadget id="calculator">2 + 3 + 4 + 5 + 6</gadget>
<output>20</output>

<result>20</result>