function m=m9(n)
q=zeros(9,1);
q(1)=n;
for i=1:8
 q(i+1)=floor(q(i)/2);
end 
m=zeros(3,3);
for i=0:2
 for j=1:3
  m(i+1,j)=(-1)^q(3*i+j);
 end
end
end
