Let ABC be a triangle inscribed the circle (O) and A' is a fixed point on (O). P moves on BC, K belongs to AC so that PK is always parallel to a fixed line d. The circumcircle of triangle APK cuts the circle (O) at a second point E. AE cuts BC at M. A'P cuts the circle (O) at a second point N. Prove that the line MN passes through a fixed point.