CR-MO 2013 G3

Let $ABCD$ be a rectangle with center $O$ such that $\angle DAC = 60^o$ . Bisector of $\angle DAC$ cuts a $DC$ at $S$ , $OS$ and $AD$ intersect at $L$ , $BL$ and $AC$ intersect at $M$ . Prove that $SM \parallel CL$ .