how it is getting this value in reg exp for php

how it is getting this value in reg exp for php

<li><b>Paperback:</b> 367 pages</li>

i need only "367"

i am using strpos and substr but now i want in regExp...

thanks

 

if (preg_match('%Paperback:</b>\s*([0-9]+)\s+pages%s', $str, $matches))
{ echo "matched $matches[1]\n"; }
else
{ echo "didn't match\n"; }

 

Thanks for this ......

it is working -> return

Paperback: 367 pages

but i want only "367"

 

if (preg_match('/\d+/', '<li><b>Paperback:</b> 367 pages</li>', $matches))
{
echo $matches[0] . "\n";
}
else
{
echo "didn't match\n";
}