and B start from two places A and B respectively, and travel back and forth between the two places at a constant speed. When A walked 6 full lengths, B walked exactly 10 full lengths. Excuse me in the process of A and B traveling together. How many times have you met in total? (Meeting head-on and catching up are considered encounters)
甲乙两人分别从AB两地出发，在两地之间匀速折返行进．当甲行走了6个全长的时候，乙恰好行走了10个全长．请问在甲乙两人行进的过程中．一共相遇了多少次？(迎面碰到和追上都算相遇)
<result>20</result>