class Stack
{
private:
    int *p;
    int top,length;

public:
    Stack(int = 0);
    ~Stack();

    void push(int);
    int pop();
    void display();
};

Stack::Stack(int size)
{
    top=-1;
    length=size;
    if(size == 0)
        p = 0;
    else
        p=new int[length];
}

Stack::~Stack()
{
    if(p!=0)
        delete [] p;
}

void Stack::push(int elem)
{
    if(p == 0)                //If the stack size is zero, allow user to mention it at runtime
    {


    }
    if(top==(length-1))     //If the top reaches to the maximum stack size
    {
        //<<"\nCannot push "<<elem<<", Stack full"<<endl;
        return;
    }
    else
    {
        top++;
        p[top]=elem;
    }
}
int Stack::pop()
{
    if(p==0 || top==-1)
    {
        //<<"Stack empty!";
        return -1;
    }
    int ret=p[top];
    top--;
    length--;

    return ret;
}