Problem 8 of Third round
Source: IX International Festival of Young Mathematicians Sozopol, Theme for 10-12 grade
September 22, 2018
graph theorycombinatorics
Problem Statement
Some of the towns in a country are connected with bidirectional paths, where each town can be reached by any other by going through these paths. From each town there are at least paths. In the country there is no such route that includes all towns exactly once. Find the least possible number of towns in this country (Answer depends from ).