function m=m64(n)
q=zeros(64,1);
q(1)=n;
for i=1:63
 q(i+1)=floor(q(i)/2);
end 
m=zeros(8,8);
for i=0:7
 for j=1:8
  m(i+1,j)=(-1)^q(8*i+j);
 end
end
end
