The present work continues the analysis of results of Dementjev et al. (2015) in order to identify the interlayer interactions of the pi-bands. Analysis of the N(E) C KVV Auger spectra of highly-ordered pyrographite showed the absence of the electron exchange between the pi-bands in 1-6 layers. Since the pi-bands are formed by the p(z) -> pi transitions, one can suggest that the pi-band occupation at each graphene layer is formed by the p(z)-electrons of this layer. Since the p(z), electrons belong to the sigma(p)-bands, the p(z) -> pi transitions in the sigma(p-)bands in each of 2-6 graphene layers result in formation of holes H, whose concentration is equal to the concentration of electrons in the pi-bands [H-i] [pi(i)]. This shows the origin of the ambipolar conductivity in graphene. The absence of the electronic interaction between the pi-bands allows a suggestion that the interaction between top six graphene layers is due to the van der Waals electrostatic attractive forces. These forces promote the p(z) -> pi transitions in each of the 2-6 graphene layers and depend on the number of graphene layers above. The N(E) C INV Auger spectra allow identification of number (1-6) of graphene layers and the pi-band occupation at each of the layer. For the first time a specification of the van der Waals forces in HOPG was done. (C) 2016 Elsevier B.V. All rights reserved.