A and B are walking towards each other from two places A and B at the same time. The place where they meet for the first time is 700 meters away from place A. After arriving at places B and A, they return immediately and meet again at a distance of 400 meters from place B. What is the distance between the places where A and B meet twice?
甲、乙两人分别从A、B两地同时相向而行，他们第一次相遇处距离A地700米，他们各地到达B、A地后立即返回，在距离B地400米处再次相遇，则甲、乙两人两次相遇地点相距多少米？
<gadget id="calculator">700 * 3</gadget>
<output>2_100</output>

<gadget id="calculator">2_100 - 400</gadget>
<output>1_700</output>

<gadget id="calculator">1_700 - 700 - 400</gadget>
<output>600</output>

<result>600</result>