class Node {
    Node left;
    Node right;
    Integer value;

    public Node getRightmostDescendant() {
        Node rightmost = this;
        while (rightmost.right != null) {
            rightmost = rightmost.right;
        }
        return rightmost;
    }

}

public class BinaryTree {
    Node root;

    public void toFlatten(Node node) {
        if (node == null) {
            return;
        }
        if (node.left != null) {
            Node moving = node.left;
            Node rightmost = moving.getRightmostDescendant();

            Node currentRight = node.right;
            node.right = moving;
            rightmost.right = currentRight;
        }
        toFlatten(node.right);
    }

}