ABC is a plane lamina of the shape of an equilateral triangle. D, E are mid points of AB, AC and G is the centroid of the lamina. Moment of inertia of the lamina about an axis passing through G and perpendicular to the plane ABC is I?. If part ADE is removed, the moment of inertia of the remaining part about the same axis is NI?/16 where N is an integer. Value of N is