A pile of porcelain bowls, packed into a box of 4 pieces, or a box of 5 pieces, or a box of 6 pieces, or a box of 7 pieces, all just finished packing. How many pieces of this pile of porcelain are at least.
一堆瓷碗，包装成4个一盒，或5个一盒，或6个一盒，或7个一盒，都正好包装完．这堆瓷器至少有多少个．
<gadget id="calculator">2 * 2 * 3 * 5 * 7</gadget>
<output>420</output>

<result>420</result>