use strict;
use warnings;
my (%hasharr, @hashkeys, $start);
while ( my $line = <> )
    chomp $line;
    next unless $line;    #skip empty lines.
    my ($head, $prod) = split /\s*:=\s*/, $line;
    foreach ($head, $prod) {
        s/^\s+//;
        s/\s+$//;
    }
    unless ( $start ) { $start = $head; };
    push ( @{$hasharr{$head}}, $prod);
    push @hashkeys, $head;
}