Dig a canal, plan to complete the task in 20 days, but actually dig 200 meters a day, and the result is completed 5 days ahead of schedule. How long is this canal in meters?
挖一条水渠，计划20天完成任务，实际每天挖200米，结果提前5天完成，这条水渠长多少米？
<gadget id="calculator">20 - 5</gadget>
<output>15</output>

<gadget id="calculator">200 * 15</gadget>
<output>3_000</output>

<result>3_000</result>