The graph between $\frac{\text{1}}{\text{u}}$ and $\frac{\text{1}}{\text{v}}$ for a thin convex lens in order to determine its focal length is plotted as shown in fig. The refractive index of lens is 1.55 and its both surface has same radius of curvatures R. Then the value of R will be ______cm (When u= objective distance, v= Image distance)