A and B have completed 32 calculation problems in total, A and C have completed 30 calculation problems in total, and B and C have completed 22 calculation problems in total. The one who completed the most is more than the least.
甲、乙两人共完成32道计算题，甲、丙两人共完成30道计算题，乙、丙两人共完成22道计算题，完成最多的比最少的多了多少道．
<gadget id="calculator">32 - 12</gadget>
<output>20</output>

<gadget id="calculator">30 - 20</gadget>
<output>10</output>

<gadget id="calculator">20 - 10</gadget>
<output>10</output>

<result>10</result>