Sum Numbers in a Linked List

#include<iostream>
using namespace std; 
  
// Node Class
class Node  
{  
    public: 
    int data;  
    Node *next;  
};  
  
  
//calculate sum of numbers in a linked list
int sumList(Node* head)
{ //base case 
  if (head == NULL) return 0;
  //recursive case
   else return head->data + sumList (head->next);
}
  
//insert a new node
void insertAtHead(Node** head, int new_data)  
{  
    //make a new node
    Node* new_node = new Node(); 
      
    //insert data in the node
    new_node->data = new_data;  
      
   //make the new_node->next points to head
    new_node->next = (*head);  
      
    //head points at new node
    (*head) = new_node;  
}  
  
//Driver Function
int main()  
{  
    //emty list
    Node* head = NULL;  
      
    //insert Data in the list
    insertAtHead(&head, 5);  
    insertAtHead(&head, 4);  
    insertAtHead(&head, 3);  
    insertAtHead(&head, 2);  
    insertAtHead(&head, 1);  
      
    cout<<"List:1->2->3->4->5 \n Sum of numbers in a list:";  
    cout<<sumList(head);  
  
    return 0;  
}