A set of eight cards with 1, 2, 3, 4, 5, 6, 7, and 8 written on them. Each person draws 2 cards from a group, at least how many people have drawn to ensure that the numbers on the 2 cards drawn by someone are mutually prime.
写有1、2、3、4、5、6、7、8的八张卡片为一组．每人从一组中抽2张，至少多少人抽过，才能保证有人抽的2张卡片上的数互质．
<gadget id="calculator">7 + 1</gadget>
<output>8</output>

<result>8</result>