For a point P in the plane, let d_{1}(P) and d_{2}(P) be the distances of the point P from the lines x - y = 0 and x + y = 0 respectively. The area of the region R consisting of all points P lying in the first quadrant of the plane and satisfying 2 ≤ d_{1}(P) + d_{2}(P) ≤ 4, is ________