3. Trip planning

You are planning a trip through Europe, which includes a visit to six different cities (Barcelona, London, Paris, Istanbul, Venice, and Prague).   The table below includes the one-way cost of traveling between the cities.   For example, the cost of traveling from Istanbul to Venice is $500.  Assume that the cost of traveling from city A to city B is the same as the cost from city B to city A.  You must end your trip at the same city where you started your trip.   Finally, you would like to avoid traveling from London to Venice because you have heard that the food is terrible on that flight.