Two spherical stars $A$ and $B$ emit blackbody radiation. The radius of $A$ is 400 times that of $B$ and $A$ emits $10^4$ times the power emitted from $B$. The ratio $\left(\frac{\lambda_A}{\lambda_B}\right)$ fo their wavelengths $\lambda_A$ and $\lambda_B$ at which the peaks occur in their respective radiation curves is :