Xiaohong and Xiaoming are running on the circular track. They start from the same place at the same time and walk in opposite directions. Xiao Hong runs 220 meters per minute, Xiao Ming runs 180 meters per minute, and they meet after 2 minutes. How many meters is the runway long?
小红和小明在环形跑道上跑步，两人从同一地点同时出发，反向而行．小红每分跑220米，小明每分钟跑180米，经过2分钟两人相遇．跑道长多少米？
<gadget id="calculator">220 + 180</gadget>
<output>400</output>

<gadget id="calculator">400 * 2</gadget>
<output>800</output>

<result>800</result>