module example003()
{
	difference() {
		union() {
			cube([30 30 30], center = true);
			cube([40 15 15], center = true);
			cube([15 40 15], center = true);
			cube([15 15 40], center = true);
		}
		union() {
			cube([50 10 10], center = true);
			cube([10 50 10], center = true);
			cube([10 10 50], center = true);
		}
	}
}

example003();