What is the equation of the quadratic graph with a focus of (3,6) and a directrix of y=4?

Given the focus and the directrix of the parabola and the information that the length from the vertex to the parabola is equal to the length from the vertex to the focus, we can say that the vertex is at (3,5) and is opening upward. Hence the general formula is (x-3) 2 = 4a (y-5). a is the length said above equal to 1. hence the equation is (x-3) 2 = 4y-20