How many numbers can be selected from 1, 3, 5, 7, ... 97, 99 so that each of them is not a multiple of another number.
从1，3，5，7，…97，99中最多可以选出多少个数，使它们当中的每一个数都不是另一个数的倍数．
<gadget id="calculator">99 / 3</gadget>
<output>33</output>

<result>33</result>