Xiao Ming and Xiao Gang walked in opposite directions at the starting point of the school's circular runway at the same time. Xiao Ming walked 63 meters per minute, and Xiao Gang walked 77 meters per minute. They met after 2.5 minutes. What is the total length of the school circular runway?
小明和小刚在学校环形跑道的起跑点同时反向走去，小明每分钟走63米，小刚每分钟走77米，经过2.5分钟相遇．学校环形跑道全长是多少米？
<gadget id="calculator">63 + 77</gadget>
<output>140</output>

<gadget id="calculator">140 * 2.5</gadget>
<output>350</output>

<result>350</result>