It is stipulated that "*" is a new operation: "a*b=a+b/(ba)", then 2*(1*2)=how much.
规定"*"是一种新运算："a*b=a+b/(b-a)"，则2*(1*2)=多少．
<gadget id="calculator">1 * 2</gadget>
<output>2</output>

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

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

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

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

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

<gadget id="calculator">2 + 1 + 2</gadget>
<output>5</output>

<result>5</result>