OJ Board

I also think that if a stack has more than one element, we can consider it has 2 elements.
I call A is the number of stack has more than 1 element and B is the number of stack has 1 element.
But I dont know where i am wrong?

Can you hint me how to solve it?

Can you hint me how to Remove the Extra Edge ?

Thanks Igor9669.
Following your link I found this course by the author but I cannot download the book (maybe this link is not avaiable).
If you have this book, can you sent to me via my email : doulce2000@yahoo.com.
Thanks you much!

Do you have any ideas to solve this problem?
....

Thanks for your help.
But can you tell me where to download "Algorithmic problem solving book"?
I looked at google but cannot find.
Thank you again.