;;;;;;;;;;;;;;;;;       
     i11111111111ii;;;;      
     1tttttttttttttt1i;;     
     1tttii;;iii11tttti;     
     1ttt;;;;;;;;;itttt;     
     1ttt;;;;;;;;;;tttt;     
     1ttt;;;;;;;;i1ttt1;     
     1ttt1111111tttt1i;;     
     1ttttttttttttt1;:::     
     1ttt1iiiii11tttt1;:     
     1ttt;::::;:;;ittt1;     
     ittt;: ::::::;1ttt;     
     ittt;::::::::;1tt1;     
     ittti;;;;;ii1ttt1;:     
     itttttttttttt11i;::     
     ;iiiiiiiiii;;;::::      
     ::::::::::::::::