Three blocks A, B and C are lying on a smooth horizontal surface, as shown in the figure. A and B have equal masses, m while C has mass M. Block A is given an inita speed v towards B due to which it collides with B perfectly inelastically. The combined mass collides with C, also perfectly inelastically `(5)/(6)th` of the initial kinetic energy is lost in whole process. What is balue of M//M?