class Vector {
    double x_, y_;
public:
    Vector(double x = 0, double y = 0);
    void print(int precision = 2, bool newLine = true);
    void truncate(double length);
    bool isOrtho(const Vector& v) const;
    static float dot(const Vector& v1, const Vector& v2);
    static float cross(const Vector& v1, const Vector& v2);
    friend ostream& operator<<(ostream& os, const Vector& v);
};

Vector::Vector(double x , double y )
{
    x_ = x ;
    y_ = y ;
}
void Vector::print(int precision , bool newLine)
{
    cout << fixed << setprecision(precision) << "(" << x_ << ", " << y_ << ")";
    if (newLine) cout << endl;
}
void Vector::truncate(double length)
{
    x_-=length;
    y_-=length;
}
bool Vector::isOrtho(const Vector& v ) const {
    return ( x_*v.x_ + y_*v.y_ == 0 );
}
float Vector::dot(const Vector& v1, const Vector& v2) {
    return (v1.x_*v2.x_ + v1.y_*v2.y_);
}
ostream& operator<<(ostream& os,const Vector& v)
{
    os << "(" << v.x_ << ", " << v.y_ << ")"  ;
    return os;
}
float Vector::cross(const Vector& v1, const Vector& v2){
    return (v1.x_*v2.y_ - v1.y_*v2.x_) ;
}