#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
struct list
{
 int field;
 struct list *ptr;
};
struct list * init(int a)
{
  struct list *lst;
  lst = (struct list*)malloc(sizeof(struct list));
lst->field = a;
  lst->ptr = lst;
  return(lst);
}
struct list * addelem(list *lst, int number)
{
  struct list *temp, *p;
  temp = (struct list*)malloc(sizeof(list));
p = lst->ptr;
  lst->ptr = temp;
  temp->field = number;
  temp->ptr = p;
  return(temp);
}
struct list * deletehead(list *root)
{
  struct list *temp;
  temp = root->ptr;
  struct list *y=temp;
    free(root);
  return(temp);
}
struct list  * deletelem(list *lst, list *root)
{
  struct list *temp;
  temp = root;
while (temp->ptr != lst)
  {
    temp = temp->ptr;
  }
  temp->ptr = lst->ptr;
  free(lst);
  return(temp);
}
void listprint(list *lst)
{
  struct list *p;
  p = lst;
  do {
  printf("%d ", p->field);
p = p->ptr;
} while (p != lst);
}
struct list * swap(struct list *lst1, struct list *lst2, struct list *head)
{
  struct list *prev1, *prev2, *next1, *next2;
  prev1 = head;
  prev2 = head;
  while (prev1->ptr != lst1)
	prev1 = prev1->ptr;
  while (prev2->ptr != lst2)
	prev2 = prev2->ptr;
  next1 = lst1->ptr;
  next2 = lst2->ptr;
  if (lst2 == next1) {
	lst2->ptr = lst1;
	lst1->ptr = next2;
	prev1->ptr = lst2;
  }
  else if (lst1 == next2) {
	lst1->ptr = lst2;
	lst2->ptr = next1;
	prev2->ptr = lst2;
}
else {
	prev1->ptr = lst2;
	lst2->ptr = next1;
	prev2->ptr = lst1;
	lst1->ptr = next2;
  }
  if (lst1 == head)
	return(lst2);
  if (lst2 == head)
	return(lst1);
  return(head);
}
int main()
{
	struct list *head, *r, *p;
	int a, n;
	system("chcp 1251");
	system("cls");
	printf("n= ");
	scanf("%d",&n);
	head = 0;
	p = 0;
	for (int i = 0; i<n; i++)
	{
		printf("Введитеэлемент:");
		scanf("%d", &a);
		if (i == 0)
		{
			p = init(a);
			head = p;
		}
		else
			p = addelem(p, a);
	}
	listprint(head);
	r=head;
while(head->field %3 == 0 )
{
    head=deletehead(head);
}
	do {
        int temp=r->field;
r=r->ptr;
        if(r==head)
            break;
        if(r->field % 3 == 0)
            deletelem(r,head);
	}
	while(1);
	printf("\n");
	listprint(head);
	getchar(); getchar();
	return 0;
}