Question 160
There are 30 cities in the country, some of them are connected by flights. The total amount of flights satisfies the following: if one does not consider any 26 cities with all flights that connect one of these cities and any other, then one can get from any of the 4 cities that is left to any other city of the four, maybe with layovers, only using flights that are left. Determine the smallest amount of flights for which the condition holds.