There are 63 students on the playground exercising, of which girls accounted for (3/7), and later a few girls came, and the number of girls reached the number of boys (8/9). How many girls came later?
操场上有63名学生在锻炼身体，其中女生占(3/7)，后来又来了几名女生，女生人数达到了男生人数的(8/9)．后来又来了几名女生？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 - (3/7)</gadget>
<output>4/7 = around 0.571429</output>

<gadget id="calculator">8 / 9</gadget>
<output>8/9 = around 0.888889</output>

<gadget id="calculator">63 * (4/7) * (8/9)</gadget>
<output>32</output>

<gadget id="calculator">63 * (3/7)</gadget>
<output>27</output>

<gadget id="calculator">32 - 27</gadget>
<output>5</output>

<result>5</result>