  Weak turbulence of magnetohydrodynamic (MHD) waves in strongly magnetized
plasma is studied when the thermal pressure is less than the magnetic field
pressure. In this situation the main nonlinear mechanism is the resonance
scattering of fast magneto-acoustic and Alfvenic waves on slow magneto-acoustic
waves. As a result, the former waves serve as the high-frequency waves with
respect to the latter ones so that the total number of HF waves - an adiabatic
invariant - conserves additionally. In the weak turbulence regime this
invariant is shown to generate the Kolmogorov type spectrum with a constant
flux of HF waves towards large-scale region. In the short-wave region another
Kolmogorov spectrum can be realized with a constant energy flux. The explicit
angle dependences for both types of turbulent spectra are found for the
propagation angles close to the direction of a mean magnetic field.
