function p2
  nr_sim = 500;
  N=zeros(1,nr_sim);
  for i=1:nr_sim
    B1=bn(0.8);
    if(B1==1)
      B2=bn(0.9);
    else
      B2=bn(0.6);
     endif
    if(B2 == 1 && B1 == 1)
      B3=bn(0.6);
    elseif(B2 ==1 && B1==0)
      B3=bn(0.2);
     elseif(B2 == 0 && B1 == 1)
      B3=bn(0.9);
     else
      B3=bn(0.4);
     endif
    if(B3 == 1)
      B4=bn(0.3);
     else
      B4=bn(0.5);
     endif
    if(B3==1)
      B5=bn(0.5);
     else
      B5=bn(0.8);
    endif
    if(B5 == 1 && B4 == 1)
      B6=bn(0.5);
    elseif(B5==1 && B4==0)
      B6=bn(0.3);
     elseif(B5==0 && B4==1)
      B6=bn(0.8);
     else
       B6=bn(0.5);
    endif
  N(i)=bin2dec(num2str([B6 B5 B4 B3 B2 B1]));
  endfor;
  bar(0:64,histc(N,0:64)/nr_sim);
  set(gca,'xlim',[0 64],'xtick',0:2:64);
endfunction

function out=bn(p)
  out=rand<p
endfunction