class MyVector {
    unsigned size_;
    unsigned capacity_;
    int* arr_;

 private:
    int pref_cap(int n);

 public:
    explicit MyVector(unsigned n = 0);

    ~MyVector();

    void Read(unsigned n);

    void PushBack(int x);

    void PopBack();

    void Insert(int x, int k);

    void Erase(int k);

    long long Sum();

    long double Mean();

    int Min();

    int Max();
};