For a batch of parts, every 5 packs will be 3 more; every 7 packs will be 3 more, and every 9 packs will be 3 more. What is the minimum number of parts in this batch?
一批零件，每5个打一包，多3个；每7个打一包，也多3个，每9个打一宝还多3个，这批零件最少有多少个．
<gadget id="calculator">5 * 7 * 9</gadget>
<output>315</output>

<gadget id="calculator">315 + 3</gadget>
<output>318</output>

<result>318</result>