Two small stones of masses and respectively, are projected simultaneously at . The stone is projected horizontally with speed from the top of a tower that is meters high and the stone is projected from the ground at a distance meters from the foot of the tower with speed at an angle of with the horizontal as shown in the figure. At time after projection, they collide in air and at that moment their velocities are mutually perpendicular. Then find
Note: give the sum of the numerical values of .