include <stdio.h>
#include <stdlib.h>
#include <limits.h>
struct Node {
 int data;
 struct Node* next;
};
int isEmpty(struct Node* head) {
 return head == NULL;
}
void push(struct Node** head, int
new_data) {
 struct Node* new_node = (struct
Node*)malloc(sizeof(struct Node));
 new_node->data = new_data;
 new_node->next = *head;
 *head = new_node;
}
void pop(struct Node** head) {
 if (isEmpty(*head)) return;
 struct Node* temp = *head;
 *head = (*head)->next;
 free(temp);