#include <iostream>
#include <cmath>

using namespace std;

class Vektor3d
{
    double x, y, z;

public:
/* ovo isto je dodato na primjer sa predavanja */
    Vektor3d()
    {
        x = 0;
        y = 0;
        z = 0;
    }
    Vektor3d(double x, double y, double z)
    {
        this->x = x;
        this->y = y;
        this->z = z;
    }
/* dovle */
    void Postavi(double x, double y, double z)
    {
        Vektor3d::x = x;
        Vektor3d::y = y;
        Vektor3d::z = z;
    }
    void Ocitaj(double &x, double &y, double &z) const
    {
        x = Vektor3d::x;
        y = Vektor3d::y;
        z = Vektor3d::z;
    }
    void Ispisi() const
    {
        std::cout << "{" << x << "," << y << "," << z << "}";
    }
    double DajX() const
    {
        return x;
    }
    double DajY() const
    {
        return y;
    }
    double DajZ() const
    {
        return z;
    }
    double DajDuzinu() const
    {
        return std::sqrt(x * x + y * y + z * z);
    }
    Vektor3d &PomnoziSaSkalarom(double s)
    {
        x *= s;
        y *= s;
        z *= s;
        return *this;
    }
    Vektor3d &SaberiSa(const Vektor3d &v)
    {
        x += v.x;
        y += v.y;
        z += v.z;
        return *this;
    }

    friend Vektor3d ZbirVektora(const Vektor3d &v1, const Vektor3d &v2)
    {
        Vektor3d v3;
        v3.x = v1.x + v2.x;
        v3.y = v1.y + v2.y;
        v3.z = v1.z + v2.z;
        return v3;
    }

/* dodato */
    friend Vektor3d &operator +=(Vektor3d &v1, const Vektor3d &v2)
    {
        v1.x += v2.x; v1.y += v2.y; v1.z += v2.z;

        return v1;
    }

    friend Vektor3d &operator *=(Vektor3d &v1, int p)
    {
        v1.x *= p; v1.y *= p; v1.z *= p;

        return v1;
    }

    friend inline Vektor3d operator +(Vektor3d v1, const Vektor3d &v2)
    {
        return v1 += v2;
    }

    friend ostream &operator <<(ostream &tok, const Vektor3d &v)
    {
        tok << "{" << v.x << "," << v.y << "," << v.z << "}";
        return tok;
    }
/* dovde */

};


int main()
{
    Vektor3d a;
    a.Postavi(1, 2, 3);
    Vektor3d b;
    b.Postavi(2, 3, 4);

    Vektor3d c;
    c = a + b;

    cout << c;

    return 0;
}