import java.util.Set;
import java.util.TreeSet;

public class Main {

    public static void main(String[] args) {

        class BTree {
            int value = 0 ;
            BTree left, right;


            public boolean contains (int v) {
                if (value == v) {
                    return true;
                }

                if (left != null && v < value) {
                    return left.contains(v);
                }
                else if (right != null && v > value) {
                    return right.contains(v);
                }
                return false;
            }
        }
        BTree tree = new BTree();
        tree.contains(100);

    }
}