**Input:** Two unentangled qubits (stored in an array of length 2).
The first qubit will be in state $|\psi\rangle = \alpha |0\rangle + \beta |1\rangle$, the second - in state $|0\rangle$
(this can be written as two-qubit state $\big(\alpha |0\rangle + \beta |1\rangle \big) \otimes |0\rangle = \alpha |00\rangle + \beta |10\rangle$).

**Goal:** Change the two-qubit state to $\alpha |00\rangle + \beta |11\rangle$.
