A plane light wave with wavelength = 0.50m falls normally on the face of a glass wedge

A plane light wave with wavelength λ = 0.50μm falls normally on the face of a glass wedge with an angle O = 30. On the opposite face of the wedge a transparent diffraction grating with period d = 2.00μm is inscribed, whose lines are parallel to the wedge's edge. Find the angles that the direction of incident light forms with the directions to the principal Fraunhofer maxima of the zero and the first order. What is the highest order of the spectrum? At what angle to the direction of incident light is it observed?