or download this
c:\@Work\Perl\monks>perl -wMstrict -le
"my $s = '1 x 12 x 123 x 1234 x 12345 x 123 x 1234 x';
...
'1 x 12 x 123 x 1234 x 12345 x 123 x 1234 x'
'1 x 12 x <a 123><b>123</b></a> x <a 1234><b>1234</b></a> x 12345 x <a
+ 123><b>123</b></a> x <a 1234>
<b>1234</b></a> x'