Adjacent Steps

A vertex is considered as a point with both its coordinates as an integer. You are initially at the origin of a plane surface. To move on the surface you have to obey the following $2$ rules: $1$.One move is counted as a vertex to an adjacent vertex. You cannot jump and only move to an adjacent vertex. For eg: If you are at $A(x, y)$ you can move to the below points only: $B(x, y+1)