The distance between places A and B is 400 kilometers. Cars A and B drive opposite each other at the same time. Car A travels 35 kilometers per hour, car B travels 45 kilometers per hour, and a pigeon travels at 50 kilometers per hour. The speed of the pigeon starts at the same time as that of A, and flies to the second car. When meeting the second car, it turns back and flies to the A car. The car just met?
A、B两地相距400千米，甲、乙两车同时从两地相对开出，甲车每小时行35千米，乙车每小时行45千米，一只鸽子以每小时50千米的速度和甲同时出发，向乙车飞去，遇到乙车又折回向甲车飞来，遇到甲车又往回飞向乙车，这样一直飞下去，鸽子飞行多少千米时，两车正好相遇？
<result>50</result>