private STNode<Key, Value> rotateRight(STNode<Key, Value> x)
	{
		STNode<Key, Value> t = x.left;
		x.left = x.left.right;
		t.right = x;

		x.N = size(x);
		t.N = size(t);

		x.h = height(x);
		t.h = height(t);

		return t;
	}