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<?php $tag = "MU"; $string = 'D109 MU, worked from home today Walked the dog, later took the kids to swimming. D110 MU. Went to the gym in the evening for the 9th time this month.'; var_export(preg_match_all("~D\K\d+(?= $tag)~", $string, $out) ? $out[0] : 'fail');

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