#include <stdio.h>
#include <stdlib.h>
int top = -1,size = 5;
int arr[25];
int isfull(){
    if(top == size-1){
        return 0;
    }else{
        return 1;
    }
}
void push(int num){
    if(isfull()){
        printf("Stack is full\n");
    }else{
        arr[++top] = num;
    }
}
int isEmpty(){
    if(top == -1){
        return 0;
    }else{
        return 1;
    }
}
void pop(){
    if(isEmpty()){
        printf("Stack is full\n");
    }else{
        top--;
    }
}
int peek(){
    if(isEmpty()){
        return 0;
    }else{
        return arr[top];
    }
}
void traverse(){
    for(int i=0;i<=top;i++){
        printf("%d ",arr[i]);
    }
}
int main() {
    int choice,num;
    while(1){
        switch(choice){
            case 1:
                scanf("%d",&num);
                push(num);
                break;
            case 2:
                pop();
                break;
            case 3:
                int n = peek();
                if(n == 0){
                    printf("Stack is Empty");
                }else{
                    printf("%d ",n);
                }
                break;
            case 4:
                traverse();
                break;
            case 5:
                exit(0);
                break;
            default:
                printf("Invalid input\n");
                break;
            
        }
    }
    return 0;
}