What concentration of nocl must be put into an empty 400l

Question

For the reaction 2NOCL(g) <--> 2NO(g) + CL₂(g), the Kc = 8.0 at a certain temperature. What concentration of NOCL must be put into an empty 4.00L reaction in order that the equilibrium concentration of NOCL be 1.00M? <--> the arrow goes both ways. Please help.