<?php
$text = "сыр пыр мир тыр cыраже истаcырыч б , купыма, ботрыва";
$regexp = "/[а-я]*[с]{1}[ы]{1}[а-я]*[ ]+/";
?>
PD9waHAKIAokdGV4dCA9ICLRgdGL0YAg0L/Ri9GAINC80LjRgCDRgtGL0YAgY9GL0YDQsNC20LUg0LjRgdGC0LBj0YvRgNGL0Ycg0LEgLCDQutGD0L/Ri9C80LAsINCx0L7RgtGA0YvQstCwIjsKJHJlZ2V4cCA9ICIvW9CwLdGPXSpb0YFdezF9W9GLXXsxfVvQsC3Rj10qWyBdKy8iOwokbWF0Y2ggPSBhcnJheSgpOwogCnByZWdfbWF0Y2goJHJlZ2V4cCwgJHRleHQsICRtYXRjaCk7CnZhcl9kdW1wKCRtYXRjaCk7CiAKPz4=