A team of hunters line up to count from 1 to 3 from left to right, and the person on the far right happens to report 3. At this time, everyone who reported 3 takes a step forward to get a new line, and then counts 1 to 3 on the new line , the person on the far right reported 1, and the person who reported 3 in the new line took a step forward. As a result, only 2 people stood up. How many people were there in total?
一个猎手班排成一行从左到右1到3报数，最右边的那个人正好报3，这时报3的人都向前一步，得到新的一行，新的一行再进行1到3报数，最右边的人报1，让新的一行报3的人再向前一步，结果只有2个人站出来，原来共有多少人？
<gadget id="calculator">3 / 1</gadget>
<output>3</output>

<gadget id="calculator">2 * 3</gadget>
<output>6</output>

<gadget id="calculator">6 + 1</gadget>
<output>7</output>

<gadget id="calculator">7 * 3</gadget>
<output>21</output>

<result>21</result>