import java.util.Stack;
import java.util.Scanner;
public class StackDemo {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Stack<String> stack = new Stack<>();
        int choice;
        while (true) {
            choice = scanner.nextInt();
            scanner.nextLine();
            switch (choice) {
                case 1:
                    String element = scanner.nextLine();
                    stack.push(element);
                    break;
                case 2:
                    if (stack.isEmpty()) {
                        System.out.println("Stack is empty. Nothing to pop.");
                    } else {
                        String poppedElement = stack.pop();
                    }
                    break;
                case 3:
                    if (stack.isEmpty()) {
                        System.out.println("Stack is empty. Nothing to peek.");
                    } else {
                        System.out.println("Top element of the stack is: \"" + stack.peek()+"\".");
                    }
                    break;
                case 4:
                    if (stack.isEmpty()) {
                        System.out.println("Stack is empty.");
                    } else {
                        System.out.println("Stack is not empty.");
                    }
                    break;
                case 5:
                    if (stack.isEmpty()) {
                        System.out.println("Stack is empty. No elements to display.");
                    } else {
                        System.out.println("Elements in the stack:");
                        for (String item : stack) {
                            System.out.println(item);
                        }
                    }
                    break;
                case 6:
                    System.out.println("Exiting program.");
                    scanner.close();
                    return;
                default:
                    System.out.println("Invalid choice. Please try again.");
            }
        }
    }
}