Two engineering teams, A and B, dig a tunnel from both ends at the same time. Team A digs 18 meters a day, and team B digs 22 meters a day. The tunnel is completed after 120 days. How many meters is this tunnel?
甲乙两个工程队分别从两端同时开凿一条隧道，甲队每天凿18米，乙队每天凿22米，120天后凿完．这条隧道长多少米？
<gadget id="calculator">18 + 22</gadget>
<output>40</output>

<gadget id="calculator">40 * 120</gadget>
<output>4_800</output>

<result>4_800</result>