For α, β, γ ∈ R, if lim_x → 0 (x^2 sin α x+(γ-1) e^x^2)/(sin 2 x-β x)=3, then β+γ-α is equal to:

For $\displaystyle \alpha, \beta, \gamma \in \mathbf{R}$, if $\displaystyle \lim _{x \rightarrow 0} \frac{x^2 \sin \alpha x+(\gamma-1) \mathrm{e}^{x^2}}{\sin 2 x-\beta x}=3$, then $\displaystyle \beta+\gamma-\alpha$ is equal to :