BSTNode rotateWithLeftChild(BSTNode k2) {
	BSTNode k1 = k2.left;
	k2.left = k1.right;
	k1.right = k2;
	return k1;
}










BSTNode rotateWithRightChild(BSTNode k1) {
	BSTNode k2 = k1.right;
	k1.right = k2.left;
	k2.left = k1;
	return k2;
}










BSTNode doubleRotateWithLeftChild(BSTNode k3) {
	k3.left = rotateWithRightChild( k3.left );
	return rotateWithLeftChild( k3 );
}











BSTNode doubleRotateWithRightChild(BSTNode k1) {
	k1.right = rotateWithLeftChild( k1.right);
	return rotateWithRightChild( k1 );
}