Cities and roads.
Source: St Petersburg Olympiad 2010, Grade 11, P3
September 14, 2017
combinatorics
Problem Statement
There are cities in country, and every two are connected by road. Businessman and Road Ministry play next game. Every morning Businessman buys one road and every evening Minisrty destroys 10 free roads. Can Business create cyclic route without self-intersections through exactly different cities?