1               $1rrrrrraaaaaaaaaaaayyyy
 2           $1xxrrrrrrrraaaaaaaaaaaayyyyyyyyy
 3        $1xxxxxrrrrrrrraaaaaaaaaaaayyyyyyy$3yyyyy$2yyyyyyyyyy
 4      $1xxxxxxxrrrrrrrraaaaa $2aaaaayyyyyyyyyyyyyyyyyyy
 5    $1xxxxxx$3xxx$1rrrrrrrraaaa $2aaaaaaayyyyyyyyyyyyyyyyy
 6  $1xxxxxx$3xxxxxr$1rrrrrrraa $2aaaaaaaaay$3yyyyyyyyy$2yyyy $1yy
 7 $1xxxxxxx$3xxx$1xxrrrrrrrra $2aaaaaaaaa$3ayyyyyyyyyyyy$1yyyyyy
 8 $1xxxxxxxxxxxxrrrrrrrr $2aaaaaaaaaaa$3yyyyyyyyyyyy$1yyyyyyy
 9$1xxxxxxxxxxxxxrrrrrr $2raaaaaaaaaaaayyy$3yyyyyyyy$1yyyyyy$1yyy
10$1xxxxxxxxxxxxxrrrrr $2rraaaaaaaaaaaayyyyy$3yy$2yyyyyy $1yyyyyy
11$1xxxxxxxx$3xxxx$1xrrrrr$2rr$3raaaaaaa$2aaaaayyyyyyyyyy $1yyyyyyyyy
12$1xxxxxxx$3xxxx$1xxrrrrrrr$3raaaaaa$2aaaaaayyyyyyy $1yyyyyyyyyyyy
13$1xxxxxxx$3xxx$1xxxrrrrrrrr$3aaaaaa$2aaaaaayyyy $1yyyyyyyyyyyyyy
14 $1xxxxxxxxxxxxrrrrrrrra $2aaaaaaaaaay $1yyyyyyyyyyyyyyyy
15  $1xxxxxxxxxxxrrrrrrr $2aaaaaaaaaaaayyyy$1yyyyyyyyyyyyy
16   $1xxxxxxx$3xxxrr$1rrrr $2raaaaaaaaaaaa $1yyyyyyyyyyyyyyy
17     $1xxxxxxxxrrrr $2rrraaaaaaaaa $1aayyyyyyyyyyyyyy
18       $1xxxxxxrrrrrrr $2aaaaaa  $1aaaayyyyyyyyyyyy
19          $1xxxrrrrrr $2raaa  $1aaaaaaayyyyyyyyy
20              $1rrrr $2rr  $1aaaaaaaaaayyyyyy
21                 $2r   $1aaaaaaaaaa