print map{
    m[ (\d+) ([a-z]?) -? (\d+|[a-z])? ]x
    and $2
         ? ( map{ $1 . $_ } $2 .. $3 )
         : $3 ? ( $1 .. $3 )
              : ( $1 )
}split ',', $s;

1 2 3 4 5 6a 6b 6c 6d 6e 7 10 11 12 13