Two cars, A and B, are traveling opposite each other at different speeds from cities A and B. They meet on the way, and the meeting point is 80 kilometers away from city A. After the encounter, the two cars continue to move forward at the same speed. The second meeting, this is the meeting point is 50 kilometers away from city A. Find the distance in kilometers between the two cities of AB?
甲乙两辆汽车分别以不同的速度从AB两城相对而行，途中相遇，相遇点距A城80千米，相遇后两车继续以原速前进，到达对方出发点后两车立即返回，在途中第二次相遇，这是相遇点距A城50千米．求AB两城相距多少千米？
<gadget id="calculator">80 * 3</gadget>
<output>240</output>

<gadget id="calculator">240 + 50</gadget>
<output>290</output>

<gadget id="calculator">290 / 2</gadget>
<output>145</output>

<result>145</result>