Xiaojun wrote 63 brush characters yesterday, and he wrote 9 more, which is three times what Xiaoying wrote yesterday. How many brush characters did Xiaoying write yesterday?
小军昨天写63个毛笔字，他再写9个就是小英昨天写毛笔字的3倍．小英昨天写了多少个毛笔字？
<gadget id="calculator">63 + 9</gadget>
<output>72</output>

<gadget id="calculator">72 / 3</gadget>
<output>24</output>

<result>24</result>