The experimental primary school organized students to participate in a queue exercise. At the beginning, 50 boys and 20 girls participated. Later, the team was adjusted, with each adjustment reducing 2 boys and adding 1 girl. After several adjustments, the number of boys and girls was equal.
实验小学组织学生参加队列演练，开始时有50个男生、20个女生参加，后来调整队伍，每次调整减少2个男生，增加1个女生，调整多少次后男、女生人数就相等了．
<gadget id="calculator">50 - 20</gadget>
<output>30</output>

<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">30 / 3</gadget>
<output>10</output>

<result>10</result>