The lattice points of (x, y) plane have coordinates (mh, nh), where m and n take on the values 0, ±1, ±2, ... and h is a positive constant. Let the four points P_1(x+h, y), P_2(x, y+h), P_3(x-h, y), P_4(x, y-h) be called the neighbors of a lattice point P(x, y) and let I be a finite and connected lattice (set of lattice points)....