RosettaCodeData/Task/Department-numbers/Perl/department-numbers-3.pl

Police  -       Fire    -       Sanitation
2       -       3       -       7
2       -       4       -       6
2       -       6       -       4
2       -       7       -       3
4       -       1       -       7
4       -       2       -       6
4       -       3       -       5
4       -       5       -       3
4       -       6       -       2
4       -       7       -       1
6       -       1       -       5
6       -       2       -       4
6       -       4       -       2
6       -       5       -       1