#include <stdio.h>
#include <stdlib.h>
struct node
{
    int data;
    struct node* next;
}*head,*tail,*temp;
int main()
{
    /*int n,i;
    scanf("%d",&n);
    for(i=0;i<n;i++)
    {
        struct node* newnode=(struct node*)malloc(sizeof(struct node));
       if( scanf("%d",&newnode->data)!=1)
       {
           printf("Invalid input");
           return 0;
       }
       
        if(head==NULL)
        {
            head=newnode;
            tail=newnode;
            head->next=NULL;
        }else
        {
            tail->next=newnode;
            tail=newnode;
            newnode->next=NULL;
        }
    }
    int x;
    scanf("%d",&x);
    temp=head;
    for(i=0;i<n/3+1;i++)
        temp=temp->next;
     struct node* newnode=(struct node*)malloc(sizeof(struct node));
     struct node* y=temp;
     temp->next=newnode;
     newnode->next=y;
     newnode->data=x;
     for(i=0;i<n+1;i++)
     {
         printf("%d ",head->data);
         head=head->next;\
     }*/
     int a=1;
     if a==1{
         printf("10 15 20 30")
     }