ii                     
                                                                     ii                     
                                                                                            
                                                                                            
nnn  nnnn      ppp  ppppp       nnn  nnnn                         iiiii             ooooo
  nnn   nn       p pp    pp       nnn   nn                            i           ooo   oo  
  nn      n      ppp      pp      nn      n                           i          oo       o 
  n       n      pp        p      n       n                           i          o         o
  n       n      p         pp     n       n                           i         oo         o
  n       n      p          p     n       n                           i         o          o
  n       n      p          p     n       n                           i         o          o
  n       n      p         pp     n       n                           i         oo         o
  n       n      pp        p      n       n                           i          o         o
  n       n      ppp      pp      n       n          ...              i          oo       o 
  n       n      p pp    pp       n       n          ...              i           ooo   oo  
nnnnn   nnnnn    p   pppp       nnnnn   nnnnn        ...         iiiiiiiiiii        ooooo   
                 p                                                                          
                 p                                                                          
                 p                                                                          
                 p                                                                          
               pppppp