#include <stdio.h>
#include <stdlib.h>
typedef struct _node{
int n;
struct _node*next;
}node;
typedef struct _linkedlist{
node*head;
}linkedlist;
void Addtotail(linkedlist*plist, int number);
void Addtohead(linkedlist*plist, int number);
void Print(linkedlist*plist);
void Free(linkedlist*plist);
int Insertnode(linkedlist*plist,int number);
void main(){
linkedlist list;
list.head=NULL;
int n,N;
do{
scanf("%d",&n);
if(n!