MathDB

13

Part of 2023 Durer Math Competition Finals

Problems(1)

fligths among 2023 cities

Source: (2022-) 2023 XVI 16th Dürer Math Competition Finals Day 2 E13

5/25/2024
A country has 20232023 cities and there are flights between these cities. Each flight connects two cities in both directions. We know that you can get from any city to any other using these flights, and from each city there are flights to at most 44 other cities. What is the maximum possible number of cities in the country from which there is a flight to only one city?
combinatorics