Blocks on table!

Classical Mechanics Level 4

At a smooth horizontal table are two identical cubes of mass \(m\), connected by a spring of rigidity \(k\). The length of spring in the un-stretched state is \(l_0\). The right cube is linked to the load mass \(m\) at the end. At some time the system is released and the system moves without initial velocity. Find the maximum distance (in cm) between blocks during the motion of the system.

[\(l_0 = 1 cm\), \(m = 3 kg\), \(k = 1000 N/m\)]