#include <cstdio>
typedef int T;
class stack{
protected:
    struct element{
        T data;
        struct element* next;
    }*begin;
    void free_stack(struct element* arg){
        if (arg){
            free_stack(arg->next);
            delete arg;
        }
    }
stack(const stack& copy){};
stack& operator=(stack& value){return *this;};
public:
    stack():begin(NULL){};
    void push(T x){
        struct element* newEl=new struct element;
        newEl->data=x;
        newEl->next=begin;
        begin=newEl;
    }
    T pop(){
        if (!begin) return -1;
        T value=begin->data;
        struct element* newEl=begin->next;
        delete begin;
        begin=begin->next;
        return value;   
    }
    void clear(){
        free_stack(begin);
        begin=NULL;
    }
    void output(){
        struct element* cur=begin;
        while(cur){
            printf("%d, ", cur->data);
            cur=cur->next;
        }
        putchar('\n');
    }
    ~stack(){
        free_stack(begin);
    }
};
int main(){
    stack st0;
    for (int i=1; i<256; i*=2)
        st0.push(i);
    st0.output();
    getchar();
    return 0;
}