Two construction teams, A and B, dig a tunnel from both ends at the same time. Team A digs 8 meters a day, and team B digs 7 meters a day. It will be opened in 245 days. How long is the tunnel?
甲、乙两个施工队分别从两头同时开凿一条隧道，甲队每天凿8米，乙队每天凿7米，245天开通，则这条隧道长多少米？
<gadget id="calculator">8 + 7</gadget>
<output>15</output>

<gadget id="calculator">15 * 245</gadget>
<output>3_675</output>

<result>3_675</result>