6 persons A, B, C, D, E and F are sitting around a rectangular table, facing towards the centre (not necessarily in the same order). One person is sitting on each of the smaller sides. Two persons are sitting on each of the bigger sides. No person is sitting at the corners. C and F are sitting on the same side. B is sitting opposite to A. F is the immediate neighbour of B. A is sitting second to the left of D.

Counting towards the left of D, how many persons are sitting between A and D?