A body of mass $$(2M)$$ splits into four masses $$\{m, M-m, m, M-m\}$$, which are rearranged to form a square as shown in the figure. The ratio of $$\frac{M}{m}$$ for which, the gravitational potential energy of the system becomes maximum is $$x : 1$$. The value of $$x$$ is _________.