my %t = ( Chicago=>[ 'Detroit', 'Cleveland', 'Denver' ], Cleveland=>[ 'Chicago', 'NYC' ], Detroit=>[ 'Chicago' ], NYC=>[ 'Cleveland' ], SF=>[ 'Denver', 'Fairbanks' ], Fairbanks=>[ 'SF','Tokyo' ], Tokyo=>[ 'Fairbanks', 'Moscow' ], Moscow=>[ 'Tokyo' ], Denver=>[ 'SF', 'Chicago' ] );