public class BinTree {
    private TreeNode root;

    public BinTree() {
        this.root = null;
    }

    public boolean contains(int element) {
        return contains(root, element);
    }

    public boolean contains(TreeNode node, int element) {
            if (node == null) {
            return false;
            }
            if (node.getMark() == element){
                return true;
            }
            if(node.getLeft()!=null){
                contains(node.getLeft(), element);
            }
            if(node.getRight()!=null){
                contains(node.getRight(), element);
            }
            return false;
    }

    public void addLeft(TreeNode node, TreeNode left){
        if (node.getLeft() != null){
            node.setLeft(left);
        }
    }

    public void addRight(TreeNode node, TreeNode right){
        if (node.getRight() != null){
            node.setRight(right);
        }
    }
}


public class TreeNode {
    private int mark ;
    private TreeNode left;
    private TreeNode right;

    public TreeNode(TreeNode left, TreeNode right){
        this.left = left;
        this.right = right;
    }

    public int getMark(){
        return mark;
    }

    public TreeNode getLeft(){
        return left;
    }

    public TreeNode getRight(){
        return right;
    }

    public void setMark(int mark){
        this.mark=mark;
    }

    public void setLeft(TreeNode left){
        this.left=left;
    }

    public void setRight(TreeNode right){
        this.right=right;
    }

}