Liquid Solution

Calculate the molar mass of nonelectrolyte solute when 6 gram of it is dissolved in 1 $\text{dm}^3$ water has osmotic pressure $2.4\ \text{atm}$ at 300 K $(R = 0.0821\ \text{atm dm}^3\ \text{K}^{-1}\ \text{mol}^{-1})$