Control stability problem

Question

Design controllers $u_1$ depending on $x$ and $u_2$ depending on $y$ such that the following system is exponentially stable: $$\dot x = A_1 x + B_1 u_1 + C_1 y \\ \dot y = A_2 y + B_2 u_2 + C_2 x \\$$ where ($A_1$, $B_1$) and ($A_2$, $B_2$) are stabilizable, respectively, and $C_1 \ne 0$, $C_2 \ne 0.$