1                  :::::::::
 2            :::::::::::::::::::
 3         :::::::::::::::::::::::::
 4       ::::::::$2cllcccccllllllll$1::::::
 5    :::::::::$2lc               dc$1:::::::
 6   ::::::::$2cl   clllccllll    oc$1:::::::::
 7  :::::::::$2o   lc$1::::::::$2co   oc$1::::::::::
 8 ::::::::::$2o    cccclc$1:::::$2clcc$1::::::::::::
 9 :::::::::::$2lc        cclccclc$1:::::::::::::
10::::::::::::::$2lcclcc          lc$1::::::::::::
11::::::::::$2cclcc$1:::::$2lccclc     oc$1:::::::::::
12::::::::::$2o    l$1::::::::::$2l    lc$1:::::::::::
13 :::::$2cll$1:$2o     clcllcccll     o$1:::::::::::
14 :::::$2occ$1:$2o                  clc$1:::::::::::
15  ::::$2ocl$1:$2ccslclccclclccclclc$1:::::::::::::
16   :::$2oclcccccccccccccllllllllllllll$1:::::
17    ::$2lcc1lcccccccccccccccccccccccco$1::::
18      ::::::::::::::::::::::::::::::::
19        ::::::::::::::::::::::::::::
20           ::::::::::::::::::::::
21                ::::::::::::