function [Y,Xt] = maxYpsi(P,m,n)
yy = [];
XXt = {};
F = zeros(m^n,1);
for t=1:n
  dimx = repmat([m],[1 t]);
  for xi = 1:m^t
    Xt = ind2coord(xi,dimx);
    [Ef1,K1] = condexp(P,F,Xt         ,m,n);
    [Ef0,K0] = condexp(P,F,Xt(1:end-1),m,n);
    K = K1 - K0;
    fv = Psi(K,m,n);
    yy(end+1) = fv;
    XXt{end+1} = Xt;
  end
end
[Y,yind] = max(yy);
Xt = XXt{yind};
return