use strict;
use warnings;
use Autodie;
open my $FH, '<', 'jzelkowsz.dat';
my %data;
while (my $pair = do{ $/ = ', ';<$FH>}) {
    my ($numeric, $alpha) = split qr/,/, $pair;
    push @{$data{$numeric}}, $alpha;
}
foreach  my $num (sort keys %data) {
    $" = ',';
    $\ = "\n";
    print "$num|@{$data{$num}}";
}