Calculation: 1995-1992+1989-1986+...+9-6+3.
计算：1995-1992+1989-1986+…+9-6+3．
<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<gadget id="calculator">1_995 - 3</gadget>
<output>1_992</output>

<gadget id="calculator">1_992 / 3 / 2</gadget>
<output>332</output>

<gadget id="calculator">3 * 332</gadget>
<output>996</output>

<gadget id="calculator">996 + 3</gadget>
<output>999</output>

<result>999</result>