Brain teaser: locks, keys and gifts
A brain teaser that remains open in Yao class WeChat group, up to the time of writing of this entry. See if it interests you and if you can solve it.
文章来源：
Author：Gee Law’s Blog
link：https://geelaw.blog/entries/brain-teaser-lock-key-gift/?utm_source=feed&utm_medium=rss