Please help on this analytic mechanics problem. Thank you

4. Consider the situation shown in the diagram below in which two identical spherical masses of radius R and mass m have their centers on a radial line from a third larger spherical mass M. The two small spheres are just in contact, and their point of contact is at a distance 1 from the center of the sphere M. The two spheres m are now released to fall toward the mass M. (a) What is the condition on the ratio of the masses m and M such that the two small spheres m remain in contact as they begin their acceleration toward M? (b) Assuming that the condition (a) is satised, what is the initial acceleration of the two-sphere system? . w