Xiao Ming and Xiao Jun are running on the circular runway of the school. They start from the same point and walk in opposite directions. Xiao Ming runs 4 meters per second, and Xiao Jun runs 6 meters per second. After 60 seconds, the two meet. The circumference of the runway is How much rice?
小明和小军在学校环形跑道上跑步，两人从同一点出发，反向而行，小明每秒跑4米，小军每秒跑6米，经过60秒两人相遇，跑道的周长是多少米？
<gadget id="calculator">4 + 6</gadget>
<output>10</output>

<gadget id="calculator">10 * 60</gadget>
<output>600</output>

<result>600</result>