Define the operation "*": a*b=a*b+b, such as 2*3=2*3+3=9, then (4*5)*2=how much
定义运算"*"：a*b=a*b+b，如2*3=2*3+3=9，则(4*5)*2=多少
<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">20 + 5</gadget>
<output>25</output>

<gadget id="calculator">25 * 2</gadget>
<output>50</output>

<gadget id="calculator">50 + 2</gadget>
<output>52</output>

<result>52</result>