Hello! I want to say in advance that I can make mistakes, and please don't to judge strictly. Because, I'm beginner in English! I am learning graphs. I understood theory of graphs, but I can't solve problems on graphs. I saw many problems which calls "easy", but it isn't easy for me. Yes, I know what I need a practise! But I didn't solve even this the easiest problem! I want to you send the easiest problem for you, and I'll to try solve it!