Between any two cities of a country consisting of 2017 cities one-way flights are organized so that there is at least one departure from each city. Determine the maximal possible value of k such that no matter how these flights are arranged there are k cities reachable from any city of a country by using of at most two flights.
Correct Solutions by,
- Toshihiro Shimizu, Kawasaki, Japan
- Tomas Jurik, Kosice, Slovakia
- Hasan Zubeyr Demir, Özel Çaglayan Fen Lisesi, Ankara
- Ömer Avcı, Bogaziçi University
- Batuhan Bayır, Ankara University
- Solution: http://www.fen.bilkent.edu.tr/~cvmath/Problem/1711a.pdf