A young’s double slit interference arrangement with slits  S1 and S2 is immersed in water (refractive index= 4/3) as shown in the figure. The positions of maxima on the surface of water are given by  x2=p2m2λ2−d2, where  λ is the wavelength of light in air (refractive index=1), 2d is the separation between the slits and m is an integer. The value of  p is