count numbers in string or count char in string

<?php

$str = 'ssssssssssss12312312312 fgdsfdsfsdf fdsfdsfdsf 432432432432 efefdsfdsfdsf frfdsf334334';
//Number only
$num_only = preg_replace("%[^\d]+%mi", '', $str);
//String Count
$res = abs(strlen($str) - strlen($num_only));
if(preg_match('/(?=.*[A-Za-z0-9])[A-Za-z0-9, .!@#$%^&*()_]{3,100}/',$str) && $res >=3)
{
echo "Succ";
}else
{
echo "Err";
}
?>