A and B set off from A and B at the same time, and walk towards each other. After reaching the starting point of the other party, they immediately return by the same road. If the first meeting is 600 meters away from A, and the second meeting is 400 meters away from A, how many meters will A and B meet?
甲乙两人同时从A、B两地出发，相向而行，走到对方出发点后，立即按原路返回．如果第一次相遇地点距A地600米，第二次距离A地400米，那么A、B相聚多少米？
<gadget id="calculator">600 * 3</gadget>
<output>1_800</output>

<gadget id="calculator">1_800 + 400</gadget>
<output>2_200</output>

<gadget id="calculator">2_200 / 2</gadget>
<output>1_100</output>

<result>1_100</result>