#! /usr/local/bin/perl -w

use strict;
use warnings;

use File::Path 'mkpath';

my %fd;
my $root = 'cache';

$|=1;
while (<>) {
    chomp;
    my @arr = split //, $_, 4;
    my $fd;
    if (@arr < 4) {
        if (!$fd{1}{$arr[0]}) {
            my $dir = "$root/$arr[0]";
            mkpath $dir;
            open $fd{1}{$arr[0]}, '>', "$dir/list.txt" or die "open $dir/list.txt";
        }
        $fd = $fd{1}{$arr[0]};
    }
    else {
        if (!$fd{n}{$arr[0]}{$arr[1]}{$arr[2]}) {
            my $dir = "$root/$arr[0]/$arr[1]/$arr[2]";
            mkpath $dir;
            open $fd{n}{$arr[0]}{$arr[1]}{$arr[2]}, '>', "$dir/list.txt" or die "open $dir/list.txt";
        }
        $fd = $fd{n}{$arr[0]}{$arr[1]}{$arr[2]};
    }
    print $fd "$_\n";
    print "." unless $. % 5000;
}