Gain of an active filter without calculating the transfer function with two OP-AMP's
It looks like the gain will be zero.

There is a feedback path from the output of the lower opamp to the input of the upper and back through R3 and R4 to the lower opamp.  The feedback is negative as the lower opamp negative input receives the direct output of the upper opamp while the signal is attenuated by R4 and R5 to the non-inverting input.  This statement would not be true if R5 did not exist. This feedback will ensure that the system is DC stable but does not define the gain if Vi is not zero.

Since C2 does not exist the voltage across R3 must be zero (no current into the input of either opamp).

Because there is feedback the opamps will change their output in such a fashion to make the input voltage difference of the opamps zero.

If the voltage across R3 is zero and the voltage across the opamp inputs is zero, so must the voltage across R4.

If the voltage across R4 is zero, the current is zero so the voltage across R5 is also zero as the only current through R5 is that from R4.

If the voltage across R4 and R5 are both zero the output voltage V0 must also be zero independent of the input V1.