On an 800-meter circular runway, A and B are running back to back on the starting line at the same time. When the two meet, A travels three times as far as B. At this time, B continues to run, and A chases after B in the opposite direction, and the two meet again. How many meters did A run from the beginning to the second meeting B?
一个800米的环形跑道，甲、乙同时在起跑线背向而行，两人相遇时，甲行的路程是乙的3倍．这时乙继续跑，甲反向去追乙，二人再次相遇．甲从开始跑到第二次遇到乙共跑了多少米？
<gadget id="calculator">800 * 2</gadget>
<output>1_600</output>

<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">1_600 / 4</gadget>
<output>400</output>

<gadget id="calculator">1_600 - 400</gadget>
<output>1_200</output>

<result>1_200</result>