First Thanks for every one spend time to prepare an contests to us I really Appreciate that.
Tutorials here are very weak comparable with Topcoder (vexorian make his best to make every thing as simple as possible).
Really most of tutorials here need another tutorials to explain it
The weird thing I noticed is when writer write a tutorial for his problemset write this sentence.
It's Obvious... , It's Easy to notice... , and something like that.
when you see this phrase almost he will tell us something neither Obvious nor understandable to us some of writers write something like that , It's obvious that this problem has an optimal subproblems so dp will work :) (Really THANKS for your neat explanation :) )
If it's obvious to me why then I'm reading this tutorial now ?
goto google & write "it's obvious codeforces" or click here you will see a good results.
Thanks & hope you got my words in a right way