Point(1) = {0, 0, 0};
Point(2) = {2, 0, 0};
Point(3) = {2, 3, 0};
Point(4) = {0, 3, 0};
Line(1) = {1, 2};
Line(2) = {2, 3};
Line(3) = {3, 4};
Line(4) = {4, 1};
Line Loop (5) = {1, 2, 3, 4};
Plane Surface (6) = {5};

Physical Line (1) = {1, 2, 3, 4};
Physical Surface (2) = {6};
