#include <stdio.h>
#include <stdlib.h>
void createList();
void printList();
void insertAtLast();
int countNode();
void deleteFromMid();

typedef struct Database{
int d;
struct Database *n;
}node;

node *h;

int main(void) {
  createList();
  printList();
  insertAtLast();
  printList();
  deleteFromMid();
  printList();
  printf("%d",countNode());
  return 0;
}

void insertAtLast(){
  printf("Enter Data : ");
  int a;
  scanf("%d",&a);
  node *list=h;
  while(list->n){
    list=list->n;
  }
  node *tmp=(node*)malloc(sizeof(node));
  tmp->d=a;
  tmp->n=NULL;
  list->n=tmp;
}

void deleteFromMid(){
  node *list=h;
int c=countNode();
c= (c%2==0)?c/2:(c/2)+1;
int i=1;
while(i<(c-1)){
  list=list->n;
  i++;
}
node *tmp=list->n;
list->n=list->n->n;
free(tmp);
}

int countNode(){
  node *list=h;
  int i=0;
  while(list){
    i++;
    list=list->n;
  }
  return i;
}

void createList(){

node *n1=(node*)malloc(sizeof(node));
node *n2=(node*)malloc(sizeof(node));
node *n3=(node*)malloc(sizeof(node));
node *n4=(node*)malloc(sizeof(node));
n1->d=1;
n1->n=n2;
n2->d=2;
n2->n=n3;
n3->d=3;
n3->n=n4;
n4->d=4;
n4->n=NULL;
h=n1;
}

void printList(){
  node *list=h;
  while(list){
    printf("%d ",list->d);
    list=list->n;
  }
  printf("\n");
}