The figure show a smooth track, a part of which is a circle of radius ‘R’. A block of mass ‘m’ is pushed against a spring of spring constant K fixed at the left end and is then released. The initial compression of the spring so that the block presses the track with a force ‘mg’ when it reaches the point P, where the radius of the track is horizontal is $\sqrt{\frac{\text{nmgR}}{\text{k}}}$, the value of n is