  A novel hybrid scheme is proposed. The {\it ab initio} LDA calculation is
used to construct the Wannier functions and obtain single electron and Coulomb
parameters of the multiband Hubbard-type model. In strong correlation regime
the electronic structure within multiband Hubbard model is calculated by the
Generalized Tight-Binding (GTB) method, that combines the exact diagonalization
of the model Hamiltonian for a small cluster (unit cell) with perturbation
treatment of the intercluster hopping and interactions. For undoped
La$_2$CuO$_4$ and Nd$_2$CuO$_4$ this scheme results in charge transfer
insulators with correct values of gaps and dispersions of bands in agreement to
the ARPES data.
