template<class T1, class T2>
class Duo
{
public:
	Duo(const T1 & _a, const T2 & _b) : a(_a), b(_b) {}
	Duo() {}
	T1 a; T2 b;
};

template<class T1, class T2, class T3>
class Trio
{
public:
	Trio(const T1 & _a, const T2 & _b, const T3 & _c) : a(_a), b(_b), c(_c) {}
	Trio() {}
	T1 a; T2 b; T3 c;
};

template<class T1, class T2, class T3, class T4>
class Quartett
{
public:
	Quartett(const T1 & _a, const T2 & _b, const T3 & _c, const T4 & _d) : a(_a), b(_b), c(_c), d(_d) {}
	Quartett() {}
	T1 a; T2 b; T3 c; T4 d;
};