In the figure shown, the two identical balls of mass M and radius R each, are placed in contact with each other on a frictionless horizontal surface. A third ball of mass M and radius R/2 is coming down vertically and has a velocity $v_0$when it simultaneously hits the two balls. The third ball comes to rest after collision. Then the speed of the each of the bigger balls just after collision is $v_0/\sqrt{n}$ (Assume that there is no friction between the balls) where ‘n’ is ___