((1988+1989*1987)/(1988*1989-1))=how much.
((1988+1989*1987)/(1988*1989-1))=多少．
<gadget id="calculator">1_989 * 1_987</gadget>
<output>3_952_143</output>

<gadget id="calculator">1_988 + 3_952_143</gadget>
<output>3_954_131</output>

<gadget id="calculator">1_988 * 1_989</gadget>
<output>3_954_132</output>

<gadget id="calculator">3_954_132 - 1</gadget>
<output>3_954_131</output>

<gadget id="calculator">3_954_131 / 3_954_131</gadget>
<output>1</output>

<result>1</result>