Hi, everybody, and welcome to the Codeforces Beta Round #9!

I'm its author. :) I've tried to make problems easy to read and funny. I’d like to say thank you to Mike Mirzayanov (for choosing problems for the contest and everything he’s done to organize it), to Igor Kudryashov (for checking author's solutions and making test generators), to Dima Matov (for correcting everything :)) and, of course to Julia Satushina (for excellent translations of the problems’ legends).

I'd like to remind you that if you have any questions on the problems, the best way to ask them is to use the web interface on the problems page.

I believe that the contest will be interesting to you, dear participants! I’m looking forward to seeing your suggestions here.

Good luck!

"It is known that Yakko and Wakko are true gentlemen, that's why if they

bothbothword is unnecessary and injurious.hmm... it's my mistake, I'm sorry

you are right, thanks

... it's

myfault :(( I must have read the Russian statement not carefully enough. I thought the males should have the same amount of points at the same time.So, Alex, you shouldn't have thanked me :'(

Your mistake is a very small epsilon of countable, but very big piece of goods You made.

This problem was the most AC'eeded in the contest. Don't punish yourself too much.

I solve it using sprintf() all the number from 1 to n, then searching those numbers which have digits other than '1' or '0' ( in that case i didnot increment the counter) otherwise i incremented the counter.

My code passed cases till case 14 where it gave "time limit exceeded"

Thanks

ncan be as large as 10^{9}, so testing them all is not a good idea.Hint: try "thinking backwards".