There is a classmate standing every 2 meters on both sides of the 100-meter runway. These students start from one end and stand according to the rule of two girls first and then one boy. How many girls are there among these classmates?
在100米的跑道两侧每隔2米站立着一个同学．这些同学从一端开始，按先两个女生，再一个男生的规律站立着．这些同学中共有多少个女生？
<gadget id="calculator">100 / 2</gadget>
<output>50</output>

<gadget id="calculator">50 + 1</gadget>
<output>51</output>

<gadget id="calculator">51 / 3</gadget>
<output>17</output>

<gadget id="calculator">17 * 2</gadget>
<output>34</output>

<gadget id="calculator">34 * 2</gadget>
<output>68</output>

<result>68</result>