<?php
    date_default_timezone_set('Europe/Sofia');
//    $numbersString = 'Th1s 12# is _43$ just %2^ random5text!!1!';
//    $dateString = '2014-12-22, this is today! Good luck with the exam. Yesterday was 21/12/2014. Three years ago was Friday 22-12-2011 and it was also working day, but 2011-12-24 was not!';
    $numbersString  = $_GET['numbersString '];
    $dateString = $_GET['dateString'];

    $numbersPattern = '/[^A-Za-z0-9](\d+)[^A-Za-z0-9]/';
    $datesPattern = '/\d{4}-\d{2}-\d{2}/';

    preg_match_all($numbersPattern, $numbersString, $numbers);
    preg_match_all($datesPattern, $dateString, $dates);

    $sum = 0;
    foreach ($numbers[1] as $number) {
        $sum += (int)$number;
    }

    $sum = strrev($sum);

    if (count($dates[0])) {
        echo "<ul>";
        foreach ($dates[0] as $date) {
            $currDate = $date;
            $dateObject = new DateTime($currDate);
            $dateObject->modify("+$sum days");
            $formatedDate = $dateObject->format('Y-m-d');
            echo "<li>$formatedDate</li>";
        }
        echo "</ul>";
    } else {
        echo "<p>No dates</p>";
    }
?>