Block and bead

A block rests on a spring and oscillates vertically with a frequency of f and an amplitude of A. A tiny bead is placed on top of the oscillating block just as it reaches its lowest point. Assume that the bead's mass is so small that its effect on the motion of the block is negligible. At what distance from the block's equilibrium position does the bead lose contact with the block?

Do I simply find the point where the force of gravity of the bead is equal and opposite to the acceleration (times bead mass) of the spring?