#include <iostream>
using namespace std;

struct Number
{
    int value;
public:
    Number(int v)
    {
        value = v;
    }
    Number operator+(Number &n)
    {
        Number result(0);
        result.value=value + n.value;
        return result;
    }

    void display()
    {
        cout << value << endl;
    }
};

int main()
{
    Number n1(5);
    Number n2(10);
    Number n3 = n1 + n2; /// Number n3 = n1.operator+(n2);
    n3.display();
    Number n4= n1+n2+n3; ///Number n4 = n1.operator+(n2.operator+(n3));
    n4.display();
}