A batch of homework books, no matter the average distribution to 10 students or the average distribution to 12 students, there are still 4 books left. How many copies are there at least in this batch of homework?
一批作业本，不论平均分给10位学生还是平均分给12位学生，都还剩4本．这批作业本至少有多少本？
<gadget id="calculator">2 * 5 * 2 * 3</gadget>
<output>60</output>

<gadget id="calculator">60 + 4</gadget>
<output>64</output>

<result>64</result>