#!/usr/bin/env perl

use strict;
use warnings;
use autodie;

my $infile = 'pm_11140267_input.txt';
my $min_to_keep = 2; # 30 for production
my %data;

{
    open my $fh, '<', $infile;

    while (<$fh>) {
        chomp;
        my (undef, $col2, $col3) = unpack 'A15xA10xA13';
        push @{$data{$col3}}, $col2;
    }
}

# For demo only:
print "Interim results:\n";
use Data::Dump;
dd \%data;

print "\nWanted output data:\n";

for (sort keys %data) {
    next if @{$data{$_}} < $min_to_keep;
    print "$_: ", join(', ', @{$data{$_}}), "\n";
}