A and B start from both places A and B at the same time and walk toward each other. When they meet, B travels 100 meters longer than A. If A starts at a distance of 220 meters from the midpoint of AB and increases to 3 times the original speed, then When they met, A traveled 100 meters further than B, find the distance between A and B.
甲、乙两人从A、B两地同时出发相向而行，相遇时乙比甲多行了100米，如果甲出发后在距离AB中点220米处把速度提高到原来的3倍，则相遇时甲比乙多行了100米，求A、B两地的距离．
<result>900</result>