The diagonals AC and BD of a rhombus ABCD intersect at the point (3, 4). If \( BD = \frac{2}{\sqrt{2}} \), \( A = (1, 2) \), \( A = (\alpha, \beta) \), \( D = (\gamma, \delta) \), and \( \alpha<\delta<\gamma<\beta \), then \( \beta + \gamma - \delta = \dots \)