Newtons law pully questions?

Question

Block B,with mass 5.00 , rests on block A, with mass 8.00, which in turn is on a horizontal tabletop (thefigure ). There is no friction betweenblock A and the tabletop, but the coefficient of static friction between block A and block B is 0.750. Alight string attached to block A passes over africtionless, massless pulley, and block C is suspended from the other end of the string. What is the largest mass thatblock C can have so that blocks A and Bstill slide together when the system is released from rest?