public class IntTree<T>{

    private class Node{

        int     key;
        T       value;
        Node    less,more;

        public Node(int key, T value){
            this.key=key;
            this.value=value;
        }

        public T get(int key){
            if(this.key==key) return value;

            Node child=key>this.key?more:less;
            if(child==null) return null;

            return child.get(key);
        }

        public void set(int key, T value){
            if(this.key==key) this.value=value;
            else if(key>this.key){
                if(more==null) more=new Node(key, value);
                else more.set(key, value);
            }
            else{
                if(less==null) less=new Node(key, value);
                else less.set(key, value);
            }

        }

    }

    private Node root;

    public void set(int key, T value){
        if(root==null) root=new Node(key, value);
        else root.set(key, value);
    }

    public T get(int key){
        if(root==null) return null;
        return root.get(key);
    }

    public void clear(){
        root=null;
    }
}