8th Balkan Mathematical Olympiad Problems 1991

8th Balkan Mathematical Olympiad Problems 1991A1.  The circumcircle of the acute-angled triangle ABC has center O. M lies on the minor arc AB. The line through M perpendicular to OA cuts AB at K and AC at L. The line through M perpendicular to OB cuts AB at N and BC at P. MN = KL. Find angle MLP in terms of angles A, B and C.