#!/usr/bin/env perl -l

use strict;
use warnings;
use autodie;

my $input_file = 'pm_1168253_reformat_input_INPUT.txt';
my $output_file = 'pm_1168253_reformat_input_OUTPUT.txt';

my %reformat;
my $re = qr{^(H\d+,\d+,)(.*)$};

{   
    open my $in_fh, '<', $input_file;

    while (<$in_fh>) {
        next if $. == 1;
        chomp;
        /$re/;
        push @{ $reformat{$1} }, $2;
    }
}

{
    open my $out_fh, '>', $output_file;
    print $out_fh $_, join ' ', @{ $reformat{$_} } for keys %reformat;
}