How to print just numbers includes in Subject using POP3Client Module.

How to print just numbers includes in Subject using POP3Client
Module.
Please Help

use Mail::POP3Client;


$pop = new Mail::POP3Client( USER => "xxxxxxxxxxxxxxxxx",
PASSWORD => "xxxxxxxxxx",
HOST => "xxxxxxxxxx" ),
TIMEOUT => 1;
for ($i = 1; $i <= $pop->Count(); $i++) {
foreach ( $pop->Head( $i ) ) {
/^(From|Subject):\s+/i and print $_, "\n";
}
print "\n";
sleep 5;
}