Production of charged $\pi$-mesons in exclusive $B_c\to V(P)+n\pi$ decays

The paper is devoted to vector or pseudoscalar heavy quarkonia production J/\psi, \psi(2S), B_{s} or B_s^* in association with five charged \pi-mesons in exclusive B_c-meson decays. Using available formfactors parameterizations and spectral functions of $W\to 5\pi$ transition we obtain branching fractions of these decays and distributions over invariant mass of (5\pi)-system.