#include <iostream>

using namespace std;

template<typename T>
class Vector
{
private:
    T *Array;
    int Size;
    int maxSize;
public:
    Vector()
    {
        Array = NULL;
        Size = 0;
        maxSize = 1;
    }

    ~Vector()
    {
    delete[] Array;
    }

    Vector(int n)
    {
        Size = n;
        Array = new T[n];
        maxSize = n * 2;
    }

    Vector(const Vector<T> &Construct)
    {
        Array = new T[Construct.maxSize];
        int i = 0;
        while(i < Construct.Size)
        {
            Array[i] = Construct.Array[i];
            i++;
        }

        Size = Construct.Size;
        maxSize = Construct.maxSize;
    }

    int Lenght()
    {
        return Size;
    }

    void Push_back(T Value)
    {
        if(Size == maxSize)
        {
            maxSize = maxSize * 2;
            T *cashArray = new T[maxSize];

            int i = 0;
            while(i < Size)
            {
                cashArray[i] = Array[i];
                i++;
            }
            delete[] Array;

            Array = cashArray;
            delete[] cashArray;
        }
        Array[Size] = Value;
        Size++;
    }

    void Pop_back()
    {
        if(Size > 0)
        {
            T *cashArray = new T[maxSize];

            int i = 0;
            while(i < Size-1)
            {
                cashArray[i] = Array[i];
                i++;
            }
            delete[] Array;

            Array = cashArray;

            Size--;
        }
    }

    void Reserve(int border)
    {
        T *cashArray = new T[border];

        int i = 0;
        while(i < border)
        {
            cashArray[i] = Array[i];
            i++;
        }
        delete[] Array;

        Array[i] = cashArray[i];

        Size = border;
    }

    void Resize(int FirstB, int SecondB)
    {
        if(FirstB > SecondB) swap(FirstB, SecondB);

        FirstB--;
        int newSize = SecondB - FirstB;
        if(Size - SecondB < 0) newSize = Size - FirstB;
        T *cashArray = new T[newSize];

        int i = 0;
        while(i < newSize)
        {
            cashArray[i] = Array[FirstB];
            i++;
            FirstB++;
        }
        delete[] Array;

        Array = cashArray;

        Size = newSize;
    }

    T& operator[](int index)
    {
        return Array[index];
    }
};