my @pretty = sort
{
   my @a = $a =~ /^(.+?)(\d*)$/;
   my @b = $b =~ /^(.+?)(\d*)$/;
   return ( $a[0] cmp $b[0] ) ||
         ( $a[1] && $b[1] && $a[1] <=> $b[1] ) ||
         ( $a[1] && 1 ) || ( $b[1] && -1 );
} @not_so_pretty;