my ($street, $number) = 
    $address=~/
               ^(.+?)           # capture street name
               \s+              # ignore following whitespace      
               (?:nr\.\s*){0,1} # ignore optional "nr." and trailing whitespace
               \w+?             # ignore alphanumerics which come before...
               (\d+)			# capture digits followed by...
			   -\d+ \s* $       # ignore a hyphen, extra digits and end of line
              /x;