Partial derivatives

You find yourself at point $(x,y,z) = (0,0,1)$ on a mountain with a shape such that the terrain can be described by the function $z = -x^2 - y^2 + 2y + 1$; where $x, y$ are coordinates analogous to latitude and longitude, respectively, and $z$ is the elevation of the terrain. If we say that the positive part of the $x$ axis corresponds to the $E$ (East) in a compass, the negative part to $W$(west), and the positive part of the $y$ axis corresponds to $N$(North), while the negative part corresponds to $S$ (South), in which direction you should move in order to reach the peak?