minkowski(convexity = 0) {
	group() {
		difference() {
			cube(size = [5, 5, 5], center = false);
			cube(size = [3, 3, 3], center = false);
			multmatrix([[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 1, 2], [0, 0, 0, 1]]) {
				cube(size = [2, 2, 2], center = false);
			}
		}
		difference() {
			cube(size = [5, 5, 5], center = false);
			cube(size = [3, 3, 3], center = false);
		}
	}
	cube(size = [1, 1, 1], center = false);
}

