#!/usr/bin/env perl

use strict;
use warnings;

my $root = '#';
my %tree;

while (<DATA>) {
    chomp;
    my ($id, $pid, $name) = split /,/;
    $tree{$id} = {name => $name, pid => $pid};
}

my @paths;
push @paths, concat($_, \%tree) for keys %tree;

print join(',', @$_), "\n" for sort {
    @$a <=> @$b || $a->[0] cmp $b->[0]
} @paths;

sub concat {
    my ($id, $tree, $path) = @_;
    $path = [] unless defined $path;
    push @$path, $tree->{$id}{name};

    if ($tree->{$id}{pid} ne $root) {
        concat($tree->{$id}{pid}, $tree, $path);
    }

    return $path;
}

__DATA__
15,10,name3
10,#,name1
12,10,name2
5,12,name4
8,5,name5

##</code><code>##

name1
name2,name1
name3,name1
name4,name2,name1
name5,name4,name2,name1