A satellite of mass $\frac{\mathrm{M}}{2}$ is revolving around earth in a circular orbit at a height of $\frac{\mathrm{R}}{3}$ from earth surface. The angular momentum of the satellite is $\mathrm{M}\sqrt{\frac{\mathrm{GMR}}{\mathrm{x}}}$. The value of x is _______, where M and R are the mass and radius of earth, respectively. (G is the gravitational constant)