Thread: Need help w/simple program

Could you please tell me what I am doing wrong? I am trying to overload the + operator, and output the sum of the 5 numbers (a, b, c, d, e).

Code:

#include <iostream.h>
#include <math.h>

class BigInteger{
private:
	
public:
	double a, b, c, d, e;
	void initial();
	//sum(BigInteger &one, BigInteger &two);
	friend BigInteger operator+(BigInteger);
};

void BigInteger::initial()
{
	cout << "Please enter 5 integers: " ;
	cin >> a >> b >> c >> d >> e;
}

BigInteger operator+(BigInteger &num)
{
	//BigInteger num;
	num = ;         // what do I put here???
	return num;
}

int main()
{
	BigInteger one, two;
	one.initial();
	
	cout << one.a << one.b << one.c << one.d << one.e <<endl;
	
	return 0;

}