A cascade connection of two voltage amplifier $A1$ and $A2$ is shown in the figure. The open-loop gain $A_{V0}$, input resistance $R_{in}$, and output resistance $R_{o}$ for A1 and A2 are as follows:
$A1: A_{V0} = 10, R_{in} = 10k \Omega, R_{o} = 1k\Omega$
$A2: A_{V0} = 5, R_{in} = 5k \Omega, R_{o} =200\Omega$
The approximate overall voltage gain $V_{out}/V_{in}$ is __________.
