Two cylindrical rods A and B made of different materials, are joined in a straight line. The ratios of lengths, radii and thermal conductivities of these rods are: \( \frac{L_A}{L_B} = \frac{1}{2} \), \( \frac{r_A}{r_B} = 2 \) and \( \frac{K_A}{K_B} = \frac{1}{2} \). The free ends of rods A and B are maintained at \( 400 \, \text{K} \), \( 200 \, \text{K} \), respectively. The temperature of rods interface is ___ \( \text{K} \), when equilibrium is established.