Let f(x) be a quadratic polynomial with leading coefficient 1 such that f(0)=p, p ≠ 0, and f( 1 )=1/3. If the equations f(x)=0 and f ° f ° f ° f(x)=0…

Let $\displaystyle f(x)$ be a quadratic polynomial with leading coefficient $\displaystyle 1$ such that $\displaystyle f(0)=p, p \neq 0$, and $\displaystyle f(\mathbf{1})=\frac{1}{3}$. If the equations $\displaystyle f(x)=0$ and $\displaystyle f \circ f \circ f \circ f(x)=0$ have a common real root, then $\displaystyle f(-3)$ is equal to \_\_\_\_.