function A =MatrixProdSlow(E,F,G,H)
% Mystery combination of four matrices
[n,n] = size(E);
A = zeros(n,n);
for i=1:n
for j=1:n
for k1=1:n
for k2=1:n
for k3=1:n
A(i,j) = A(i,j) + E(k1,i)*F(k1,i)*G(k2,k1)*H(k2,k3)*F(k2,k3)*G(k3,j);
end
end
end
end
end