Define the Cylinders with Massive Piston?

Assay moles of an ideal monatomic gas placed in a vertical cylinder. The top of the cylinder is blocked by a piston of mass M and cross section A. Initially the piston is set, and the gas has volume V₀ and temperature T₀ Next, the piston is free, and later than several oscillations comes to a stop. 

Ignoring friction and the heat capacity of the piston and cylinder, find the volume and temperature of the gas at equilibrium. The system is thermally isolated as well as the pressure outside the cylinder is P_0.