class Triangle
{
private:
    double length1, length2, length3;
public:
    friend Triangle operator + (const Triangle &v1, const Triangle &v2)
    {
        return Triangle (v1.length1 + v2.length1,
                         v1.length2 + v2.length2,
                         v1.length3 + v2.length3);
    }
};

class Triangle
{
private:
    double length1, length2, length3;
public:
    Triangle (double a, double b, double c)
    {
    length1 = a;
    length2 = b;
    length3 = c;
    }

    friend Triangle operator + (const Triangle &v1, const Triangle &v2)
    {
        return Triangle (v1.length1 + v2.length1,
                         v1.length2 + v2.length2,
                         v1.length3 + v2.length3);
    }
};