1                 $1_wwM $2_ww
 2                  $1MMM$2MMMM
 3                   $1MM
 4           $3_ww##############yy_
 5          $4wMMMMM$3###########$4MMMMm
 6        $4,MMMMMMMMM$3######$4MMMMMMMM0_
 7       $4wMMMMMMMMMMMMM$5MM$60MMMMMMMMMMm
 8     $4,MMMMMMMMMMMMMMM$5MMMM$60MMMMMMMMM0,
 9    $4wMMMMMMMMMMMMMMMM$5MMMMM0$6MMMMMMMMMMb
10  $4_MMMMMMMMMMMMMMMMMM$5MMMMMMM0$6MMMMMMMMM0,
11 $4_MMMMMMMMMMMMMMMMMMM$5MMMM$7M$5MMMW$6MMMMMMMMMM_
12$4_MMMMMMMMMMMMMMMMMMMM$5MMMM$7M0$5MMMW$6MMMMMMMMMM_
13   $4~MMMMMMMMMMMMMMMMM$5MMMM$7M$5MMMW$6MMMMM00~
14       $4~MMMMMMMMMMMMM$5MMMWMMM$60MM$5MMM$6~
15          $4~MMMMMMMMMM$5MMMMM$60MMM~~
16              $4~MMMMMM$5MMM$60MM~
17                  $4~MM$5M$6@~
18                    $4M