There are 8 cars, at least one of which transports 2 tons of goods, and the rest transports at least 1 ton. How many tons does this batch of goods have at least?
有8辆汽车，其中至少有一辆汽车运送2吨货物，其余的至少运1吨，这批货物至少有多少吨．
<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">7 * 1</gadget>
<output>7</output>

<gadget id="calculator">7 + 2</gadget>
<output>9</output>

<result>9</result>