#include <glob.h>

class Vector {
private:
    int* data;
    size_t _size;

public:
    Vector() {
        data = new int[];
        _size = 0;
    }

    Vector(Vector other) {
        data = other.data;
        _size = other._size;
    }

    void push_back(const int& x) {
        ++_size;
        *(data + _size) = x;
    }

    void pop_back() {
        delete (data + _size);
        --_size;
    }

    size_t size() {
        return _size;
    }

    int operator[](const size_t& i) const {
        return *(data + i);
    }

    Vector& operator=(Vector& other) {
        data = other.data;
        _size = other._size;
        return *this;
    }

    ~Vector() {
        for (size_t i = 0; i < _size; ++i) {
            delete (data + i);
        }
    }
};