#include <iostream>
using namespace std;


class MyVector
{
public:
    double x, y, z;
    MyVector& operator *= (double c)
    {
        x *= c;
        y *= c;
        z *= c;
        return *this;
    }
};

MyVector operator*(const MyVector &v, double c) {
  MyVector temp(v);
  temp *= c;
  return temp;
}

MyVector operator*(double c, const MyVector &v) {
  return v*c; // using MyVector operator*(const MyVector &v, double c)
}

ostream& operator<<(ostream&os, const MyVector& v) {
  return os << '{' << v.x << ',' << v.y << ',' << v.z  << '}';
}

int main() {
	MyVector v; v.x=1; v.y=2; v.z=3;
    
    MyVector v1 = v*2;
    cout << v1 << endl;
    MyVector v2 = 2*v;
    cout << v2 << endl;
}