Simple calculation: 5*999+5+99*7+7+3*9+3+9.
简便计算：5*999+5+99*7+7+3*9+3+9．
<gadget id="calculator">5 * 999</gadget>
<output>4_995</output>

<gadget id="calculator">99 * 7</gadget>
<output>693</output>

<gadget id="calculator">3 * 9</gadget>
<output>27</output>

<gadget id="calculator">4_995 + 5 + 693 + 7 + 27 + 3 + 9</gadget>
<output>5_739</output>

<result>5_739</result>