Functions

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