#include <cstdlib>
#include <iostream>
#include <math.h>
#include <fstream>

using namespace std;

class Vector
{
    double x,y;
  public:
    Vector(double,double);
    Vector(char*);
    void print();
    void mul(double);
    double abs();
    void load(char *);
    void save(char *);
};

Vector::Vector(double xx,double yy)
{
    x=xx;
    y=yy;
}

void Vector::print()
{
    cout << "(" << x << "," << y << ")";
}

void Vector::mul(double m)
{
    x *= m;
    y *= m;
}

double Vector::abs()
{
    return sqrt(x*x+y*y);
}

Vector::Vector(char *fname)
{
    load(fname);
}

void Vector::load(char *fname)
{
    ifstream i(fname);
    i >> x >> y;
}

void Vector::save(char *fname)
{
    ofstream o(fname);
    o << x << " " << y;
    o.close();
}


int main(int argc, char *argv[])
{
    Vector *v=new Vector(1,2);
    v->print();
    v->mul(5);
    v->print();
    cout << v->abs();
    v->save("out.txt");
    delete v;
    Vector *v2=new Vector("out.txt");
    v2->print();
    delete v2;
    return 0;
}