lc = 1e1;
Point (1) = {0, 0, 0, lc};
Point (2) = {0, 0, 1, lc};
Point (3) = {0, 1, 0, lc};
Point (4) = {0, 1, 1, lc};
Point (5) = {1, 0, 0, lc};
Point (6) = {1, 0, 1, lc};
Point (7) = {1, 1, 0, lc};
Point (8) = {1, 1, 1, lc};
Line(1) = {1, 2};
Line(2) = {2, 6};
Line(3) = {6, 5};
Line(4) = {5, 1};
Line(5) = {1, 3};
Line(6) = {3, 4};
Line(7) = {4, 2};
Line(8) = {6, 8};
Line(9) = {8, 4};
Line(10) = {3, 7};
Line(11) = {7, 8};
Line(12) = {7, 5};
Line Loop(13) = {4, 1, 2, 3};
Plane Surface(14) = {13};
Line Loop(15) = {9, 7, 2, 8};
Plane Surface(16) = {15};
Line Loop(17) = {8, -11, 12, -3};
Plane Surface(18) = {17};
Line Loop(19) = {4, 5, 10, 12};
Plane Surface(20) = {19};
Line Loop(21) = {6, 7, -1, 5};
Plane Surface(22) = {21};
Line Loop(23) = {9, -6, 10, 11};
Plane Surface(24) = {23};
Surface Loop(25) = {24, 16, 22, 14, 20, 18};
Volume(26) = {25};
Physical Surface (2) = {24};
Physical Volume (3) = {26};
