IMPLEMENTING NATURAL MERGE FOR LINKED LIST ( NOT FOR FILE )

I need u to help me correct this code of implementing NATURAL MERGE FOR LINKED LIST ( NOT FOR FILE ), I base on the ideas of natural merge on file to do it.

HERE IS MY SOURCE CODE
typedef struct NODE{
      elem data;
        struct NODE *next;
} NODE;

typedef NODE *list;

////////////////// NATURAL SORT FILE USE LINKED LIST //////////////////////

void copyrun2(list &l1, list &l2)
{
      list p2 = l2;

      list pl1 = l1;
      list pl2 = l1->next;

      while(p2->next!=NULL)
      {
              
                p2 = p2->next;
      }

      while(pl2!=NULL && pl2->data >= l1->data)
      {
            l1 = l1->next;
                pl2 = pl2->next;
      }

      p2 = pl1;
        l1->next = NULL;
      l1 = pl2;
}

void distribute2(list &l1, list &l2, list &l3)
{
      do
      {
            copyrun2(l1,l2);
            if(l1!=NULL)
                  copyrun2(l1,l3);
      }
      while(l1!=NULL);
}

void mergerun2(list &l1, list &l2, list &l3)
{
      l1 = new NODE;
      list p2 = l2->next;
      list p4 = l3->next;

      while(l2->data < p2->data && l3->data < p4->data && p2 !=NULL && p4!= NULL)
      {
            if(l2->data < l3->data)
            {
                  l1->next = l2;
                  l2 = l2->next;
                  l1 = l1->next;
                  p2 = p2->next;
            }
            else
            {
                  l1->next = l3;
                  l3 = l3->next;
                  l1 = l1->next;
                  p4 = p4->next;
            }

      }
      while(l2->data < p2->data)
      {
            l1->next = l2;
            l2 = l2->next;
            l1 = l1->next;
            p2 = p2->next;
      }
      while(l3->data < p4->data)
      {
            l1->next = l3;
            l3 = l3->next;
            l1 = l1->next;
            p4 = p4->next;
      }
}

void merge2(list &l1, list &l2, list &l3, int &R)
{
      R=0;
      list p1 = new NODE;
      cout<<"AAAAAAAAAAAAAAAAAAAAAAAAAAAA";
      while(l2!=NULL && l3!=NULL)
      {
            mergerun2(l1,l2,l3);
                R++;
      }
      while(l2!=NULL)
      {
            copyrun2(l2,l1);
            R++;
      }
      while(l3!=NULL)
      {
            copyrun2(l3,l1);
            R++;
      }
      l1 = p1;

}

void natural_list_sort(list &l1)
{
      int R;
      list l2=NULL, l3=NULL;
      do
      {
            distribute2(l1,l2,l3);
            merge2(l1,l2,l3,R);
      }
      while(R>1);
}

IN MAIN FUNCTION u CALL natural_list_sort(list &l1) to run it