In the case of a rigid rorator, i. e. two masses M1 and M2 placed on a rigid weightless rod, we start from the Schrodinger equation for two particles 1 and 2, and then we separate the movement of the center of masses. Give the formulas of both masses that we get as part of this procedure. Calculate these masses in atomic mass units for the HD molecule by approximating the masses H and D with their mass numbers.