Let \( p = (1, \frac{1}{2}, \frac{1}{3}, \frac{1}{4}) \in {R^4 \) and \( f : {R}^4 \to {R} \) be a differentiable function such that
\( f(p) = 6 \) and \( f(Ax) = A^3 f(x) \), for every \( A \in (0, \infty) \) and \( x \in {R}^4 \). The value of
\[
12 \frac{\partial f}{\partial x_1}(p) + 6 \frac{\partial f}{\partial x_2}(p) + 4 \frac{\partial f}{\partial x_3}(p) + 3 \frac{\partial f}{\partial x_4}(p)
\]
is equal to (answer in integer):}