A copper rod and an aluminium rod, each $0.50\ \text{m}$ long with a cross-section of $2.0\ \text{cm}^2$, lie side by side between a $100\ ^\circ\text{C}$ bath and a $0\ ^\circ\text{C}$ bath. How much heat flows through the pair each second? ($k$: copper $385\ \text{W m}^{-1}\text{K}^{-1}$, aluminium $205\ \text{W m}^{-1}\text{K}^{-1}$.)