Description

When you were young, have you ever  bounced balls yourself?  Counting the numbers of contiguous bouncing as much as possible! Sounds exciting, right!

小时候是不是喜欢一边颠球,一边默默数着个数,随着次数的增加心情越来越激动呢?
是不是喜欢和小伙伴们比赛看谁颠球颠的多呢?