$$ \text { Assuming ideal op-smps, the circuit represents is } $$

In the circuit, $I_{\mathrm{DC}}$ is an ideal current source. The transistors $M_1$ and $M_2$ are assumed to be biased in saturation, wherein $V_{\text {in }}$ is the input signal and $V_{D C}$ is fixed DC voltage. Both transistors have a small signal resistance of $r_{d s}$ and trans-conductance of $g_m$. The small signal output impedance of this circuit is

In the circuit, shown below, if the values of $R$ and $C$ are very large, the form of the output voltage for a very high frequency square wave input, is best represented by

The op-amps in the following circuit are ideal. The voltage gain of the circuit is ___________. (Round off to the nearest integer)