void menu(){
    Vector a;
    do{
        cout << "\n        MENU\n" << "   Choose action\n"  << "   1. Array input\n" << "   2. Array output\n";
        cout << "   3. Insert of new elements\n";
        cout << "   4. Deleting of elements\n" << "   5. Array check\n" << "   6. Exit\n";
        printf("   Command = ");
        cin >> k;
        cout << endl;
        switch(k)
        {
            case 1 : {
                a.input();
                break;
            }
            case 2 : {
                cout << "Array = ";
                a.output();
                break;
            }
            case 3 : {
                int pos, elem;
                cout << "pos = ";
                cin >> pos;
                cout << "elem = ";
                cin >> elem;
                if (a.insert(pos, elem))
                    cout << "Element was succesfuly insert\n";
                else{
                    cout << "Number out of range\n";
                }
                break;
            }
            case 4 : {
                    if (!del(a, n))
                        cout << "There are no two zero\n";
                    else
                        cout << "Elements was succesfuly delete\n";
                    break;
            }
            case 5 : {
                    if (check(a, n))
                        cout << "There are 2 equal elements\n";
                     else
                        cout << "There are no 2 equal elements\n";
                break;
            }
            default: k = 0;
        }
    }while(k);
  delete []a;
}