template <typename T1,typename T2>
class Pair
{
private:
    T1 x;
    T2 y;
public:
    Pair(T1 _x,T2 _y):x(_x),y(_y) { };
    T1 getFirst(){
        return x;
    }
    T2 getSecond(){
        return y;
    }
    Pair<T2, T1> swapElements(){
        return new Pair<T1, T2>(x,y);
    }
};