Electrolysis and its applications - class-XII

An aqueous solution of volume 500 ml, when the reaction : $ 2Ag^+(aq) +Cu(s) \leftrightharpoons Cu^{2+}(aq) +2Ag(s) $ reached equilibrium, the concentration of $ Cu^{2+} $ ions was xM. to this solution, 500 ml of water is added.at new equilibrium , the concentration of $ Cu^{2+} $ ions would be