5
       London            0.0  125.0  250.0   75.0  450.0
       Manchester      125.0    0.0   83.0  327.0  154.0
       Dunwich         250.0   83.0    0.0  223.0  243.0
       East-Grinstead   75.0  327.0  223.0    0.0   93.0
       Burnt-Norton    450.0  154.0  243.0   93.0    0.0