Complex op amps circuit
Your circuit is the well-known GIC structure invented by A. Antoniou already in 1969. This a very versatile block for realizing "active inductors" (your example) and "Frequency dependent negative resistances (FDNR)" 

There is a simple trick for easily finding the input impedance:

Assuming that both opamps are ideal, the diff. voltage across the input terminals may be set to zero. Now - because both inv. terminals are connected to each other we also can say that both non-inverting terminals have the same potential (voltage versus ground). Therefore, without modifying the properties of the whole circuit, we are allowed to swap both non-inv. terminals.

As a result (perhaps it is good to make a re-drawing) you will see that both opamp circuitries are separated (connected in series). Furthermore, you will see that the whole block consists of two NICs (Negative Impedance Converter) in series where the normally grounded resistor of the first NIC is replaced by a second NIC.

When you have the input impedance of such an NIC (simply to derive, can be found in each relevant textbook), it is no problem to find the wanted input impedance of the whole circuit.

Remark: The last structure (Two NIC in series) can be used as a GIC as well (because it has the same properties as the shown circuit - however, for ideal opamps only!). Due to the cross-wise connections, the Antoniou topology has the advantage that opamp non-idealities (finite and frequency-dependent gain) are compendsated up to a certain degree.

2nd remark: I forgot to mention that - after swapping the non-inv. input nodes - we have two different NIC circuits in series (one is short-circuit stable and the other one is open-circuit stable). Only this combination ensures stability of the whole circuit.