What is the period of oscillation of the scale?

For lunch you and your friends decide to stop at the nearest deli and have a sandwich made fresh for you with 0.100 of turkey. The slices of turkey are weighed on a plate of mass 0.400 placed atop a vertical spring of negligible mass and force constant of 200 . The slices of turkey are dropped on the plate all at the same time from a height of 0.250 . They make a totally inelastic collision with the plate and set the scale into vertical simple harmonic motion (SHM). You may assume that the collision time is extremely small.