class node
      {
      public:
      node(int i){id=i;Lchild=NULL; Rchild=NULL;}  
      node(){id=0; Lchild=NULL; Rchild=NULL;}
      node(node * n){id=n->getid(); Lchild=n->getL(); Rchild=n->getR();}
    
      int getid(){return id;}
      node *getL(){return Lchild;}
      node *getR(){return Rchild;}
      void print(){cout<<"my id = "<<id<<endl;
                   if(Lchild!=NULL){Lchild->print();}
                   if(Rchild!=NULL){Rchild->print();}
                   }
      
      void addval(int i);
      
       
      ~node(){delete Lchild; delete Rchild;}
      private:
              int id;
              node * Lchild;
              node * Rchild;
      };
      
      //**************************//
      
      void node::addval(int i)
           {
           if(i==id){cout<<"node already exists"<<endl;}
           else if(i<id)
                    {
                    if(Lchild==NULL){Lchild = new node(i);}
                    else{Lchild->addval(i);}
                    }           
           else     {
                    if(Rchild==NULL){Rchild = new node(i);}
                    else{Rchild->addval(i);}
                    }
           }