#include <iostream>

using namespace std;

typedef struct Node
{
    int number;
    struct Node *next;
} Node;

Node *makeNode(int number)
{
    Node *temp = new Node;
    temp -> number = number ;
    temp -> next = NULL;

    return temp;
}

void addLast(Node *head, Node *node)
{
    Node *current = head;

    while (current->next != NULL)
    {
        // Run until the last node in the list
        current = current->next;
    }

    current->next = node;
}

void printList(Node *head)
{
    Node *current = head;
    while (current != NULL)
    {
        cout << current->number << "->";
        current = current-> next;
    }
    cout << "NULL" << endl;
}

Node *function(Node *head)
{
    Node *head2 = NULL, *current2 = NULL;
    Node *current = head;

    while (current != NULL)
    {
        if (head2 == NULL)
        {
            head2 = current->next;
            current2 = head2;
        }
        else
        {
            current2->next = current->next;
            current2 = current2->next;
        }

        if (current->next != NULL)
        {
            current->next = current->next->next;
        }

        current = current->next;
    }

    return head2;
}

int main()
{
    Node *list1 = makeNode(2), *list2;

    addLast(list1, makeNode(4));
    addLast(list1, makeNode(8));
    addLast(list1, makeNode(16));
    addLast(list1, makeNode(24));
    addLast(list1, makeNode(46));
    addLast(list1, makeNode(50));
    addLast(list1, makeNode(7));

    cout << "List 1:" << endl;
    printList(list1);
    cout << endl;

    list2 = function(list1);

    cout << "List 1 modified:" << endl;
    printList(list1);
    cout << endl;

    cout << "List 2:" << endl;
    printList(list2);
    return 0;
}