import java.util.Scanner;

class Stack {
    Scanner sc = new Scanner(System.in);
    int top = -1;
    int stackSize=3;
    int[] stack = new int[stackSize];


    void push() {
        if(top<stackSize-1) {
            top++;
            System.out.println("n:-"+top);
            System.out.print("Enter the element you want to push :- ");
            int element = sc.nextInt();
            stack[top] = element;
            System.out.println("Element inserted");
            display();

        } else {
            System.out.println("Stack Overflow");
        }
    }

    void pop() {
        if(top>=0) {
            System.out.println("n :- "+top);
            System.out.println("Deleting last element from stack");
            System.out.println("Deleted element :- " + stack[top]);
            top--;
            display();
        }
        else {
            System.out.println("Stack Underflow");
        }

    }

    void display() {
        System.out.println(":::::STACK:::::");
        if(top==-1){
            System.out.println("Stack is Empty");
        }
        else {
            for (int i = top; i >= 0; i--)
                System.out.println("::     "+stack[i]+"    ::");

        }
        System.out.println(":::::::::::::::");

    }
}

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        Stack s1 = new Stack();
        while (true) {
            System.out.println(":::::::::::::::::::::::::::::::::::::::::::::::");
            System.out.println("1. Push Element\n2. Pop Element\n3. Display\n4. Exit");
            int input = sc.nextInt();
            switch (input) {
                case 1:
                    s1.push();
                    break;
                case 2:
                    s1.pop();
                    break;
                case 3:
                    s1.display();
                    break;
                default:
                    System.exit(0);
                    break;


            }


        }

    }
}