function r=Mrk(m,M)
   k=min(size(m,1),size(m,2))
   for i=k:1
	   S=nchoosek([1:size(m,1)],i)
	   P=nchoosek([1:size(m,2)],i)
	   for j=1:size(S,1)
		   for l=1:size(P,1)
			   if rkmax(m(S(j,:),P(l,:)),M(S(j,:),P(l,:)))==1
			   r=i
			   return
			   end
			   end
			   end
			   end