Students A and B are 1000 meters apart and walking towards each other at the same time. Student A's speed is 3 m/s, and student B's speed is 2 m/s. At the same time, a puppy runs from A to B at a speed of 6 m/s, and runs to A at the same speed after meeting B, and so on, until A and B meet each other. Ask how many meters did the puppy run during this period of time?
甲，乙两同学相距1000米，同时相向而行．甲同学速度为3米/秒，乙同学速度为2米/秒．与此同时，一只小狗以6米/秒的速度，从甲身边跑向乙，遇到乙后又以同样的速度跑向甲，…如此往返，直到甲、乙同学相遇．问在此段时间内，小狗共跑了多少米？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">1_000 / 5</gadget>
<output>200</output>

<gadget id="calculator">200 * 6</gadget>
<output>1_200</output>

<result>1_200</result>