A sheep has four feet, 10 A sheep has 60 feet. Of course, a sheep has four feet, but let's not forget that besides these four feet, a sheep has two feet, which are the horns on its head.
However, someone asked, some sheep have horns, others have no horns, so why did they end up 60 feet?
Other algorithms:
A sheep has four feet, so 10 sheep is between four feet and 40 feet.
If the other nine sheep have no feet, it is four feet, and if the other nine sheep have feet, it is 40 feet, so we only need to take a compromise data, 4~40.