#!perl
use strict;
use warnings;
use Graph::Directed;
my $graph = Graph::Directed->new;

while ( my $line = <DATA> ) {
    chomp $line;
    my ( $job, @deps ) = split( /,/, $line );
    for my $dep (@deps) {
        $graph->add_edge( $job, $dep );
    }
}

for my $job ( sort ( $graph->vertices ) ) {
    print "$job requires ";
    for ( sort ( $graph->all_successors($job) ) ) {
        print "$_ ";
    }
    print "\n";
}

__DATA__
job1,
job2,job1,
job3,job2
job4,job2
job5,job2,job4
job6,jobz
joba,job4,jobb
jobz,jobbc,job2