The distance between A and B cities is 3500 meters. Car A travels an average of 180 meters per minute, and car B travels an average of 170 meters per minute. These two cars are traveling towards each other from cities A and B at the same time. Car A travels from city A to city B. After taking a 3-minute break in the city and returning to city A, car B also rested for 3 minutes and returned to city B after going from city B to city A. How many minutes did it take for them to meet for the second time after they met for the first time?
甲、乙两城相距3500米，A车平均每分钟行180米，B车平均每分钟行170米，这两辆车同时分别从甲、乙两城相向而行，A车从甲城到乙城后休息3分钟向甲城返回，B车从乙城到甲城后也休息了3分钟返回乙城，它们第一次相遇后又经过多少分钟第二次相遇？
<gadget id="calculator">170 + 180</gadget>
<output>350</output>

<gadget id="calculator">3_500 / 350</gadget>
<output>10</output>

<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">3 - 10</gadget>
<output>-7</output>

<gadget id="calculator">30 + (-7)</gadget>
<output>23</output>

<result>23</result>