#!/usr/bin/perl
# http://www.graco.c.u-tokyo.ac.jp/~nishi/net/image/jpeg.html
# Copyright (c) 2003 NISHIMURA Daisuke

use integer;

if ($ARGV[0] =~ /^-(\d+)/) {
    $n = $1;
    shift;
} else {
    $n = 8;
}

$i = 0; $sign = 1;
$u = - $n + 1; $v = 1;
while (<>) {
  data:
    while (/(\S+)/g) {
	$q[$i] = $1;
	if (--$v == 0) {
	    $u++;
	    $sign = - $sign;
	    $i = ($sign > 0 ? ($n - 1) * $n : $n - 1)
	      + ($sign * $u > 0 ? $u : $u * $n);
	    $v = $n - abs $u;
	} else {
	    $i += $sign * (1 - $n);
	}
    }
}

print "<table>\n";
for (my $i = 0, my $k = 0; $i < $n; $i++) {
    print "<tr>";
    for (my $j = 0; $j < $n; $j++) {
	print "<td>" . $q[$k++] . "</td>";
    }
    print "</tr>\n";
}
print "</table>\n";