Teacher Zhou distributed exercise books to the students, and each person divided 7 copies and there were 7 more copies. If each person distributed 2 more copies, one student would not be able to get them. How many exercise books are there in total?
周老师给学生发练习本，每人分7本还多出7本，如果每人多发2本，就有一个同学分不到，一共有多少个练习本？
<gadget id="calculator">7 + 2</gadget>
<output>9</output>

<gadget id="calculator">7 + 9</gadget>
<output>16</output>

<gadget id="calculator">9 - 7</gadget>
<output>2</output>

<gadget id="calculator">16 / 2</gadget>
<output>8</output>

<gadget id="calculator">9 * 8</gadget>
<output>72</output>

<gadget id="calculator">72 - 9</gadget>
<output>63</output>

<result>63</result>