Mr. Wang is going to buy some exercise books as prizes to distribute to everyone. These exercise books are 2 for 2 numbers, 3 for 3 numbers, and 5 for 5 numbers. ?
王老师准备买一些练习本作为奖品发放给大家，这些练习本2个2个的数，3个3个的数，5个5个的数，都正好发完，王老师至少要买多少本作业本？
<gadget id="calculator">2 * 3 * 5</gadget>
<output>30</output>

<result>30</result>