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Anna and Bella's flights in EU

Source: KöMaL A. 701

June 21, 2018
combinatoricsgraph theoryHall s marriage theorem

Problem Statement

An airline operates flights between any two capital cities in the European Union. Each flight has a fixed price which is the same in both directions. Furthermore, the flight prices from any given city are pairwise distinct. Anna and Bella wish to visit each city exactly once, not necessarily starting from the same city. While Anna always takes the cheapest flight from her current city to some city she hasn't visited yet, Bella always continues her tour with the most expensive flight available. Is it true that Bella's tour will surely cost at least as much as Anna's tour?
(Based on a Soviet problem)