Hi I'm having calculation error is the function - fraction::GCD(int& gcd, int e, int f)

Example: If u enter 1/3 for both first and second fraction

The unsimplified fraction would be 6/9

And when u call the GCD function and do the calculation by urself u can see that it's not correct

Hope someone can help me figure it out cus I tried and can't seem to find the problem in the GCD function.

Thank You Very Much!!

```
#include <iostream>
using namespace std;
class fraction
{
public:
void plus_equal(fraction frac1, fraction frac2);
void input();
void output();
void GCD(int& gcd, int e, int f);
void simplify(int gcd, int e, int f);
private:
int num;
int denom;
};
void fraction::input()
{
cin >> num >> denom;
}
void fraction::output()
{
cout << num << "/" << denom << endl;
}
void fraction::plus_equal(fraction frac1, fraction frac2)
{
fraction frac_sum;
int a, b, c, d, e, f;
int gcd=0;
a = frac1.num;
b = frac1.denom;
c = frac2.num;
d = frac2.denom;
e = frac_sum.num=0;
f = frac_sum.denom=0;
e = ((a * d) + (c * b));
f = (b * d);
cout << "The fraction is: " << e << "/" << f << endl;
GCD(gcd, e, f);
simplify(gcd, e, f);
}
void fraction::GCD(int& gcd, int e, int f)
{
while(f != 0)
{
int temp;
temp = f;
f = e % f;
gcd = temp;
}
cout << "GCD is: " << gcd << endl;
}
void fraction::simplify(int gcd, int e, int f)
{
e = e / gcd;
f = f / gcd;
cout << "Simplified fraction is: " << e << "/" << f << endl;
}
int main()
{
fraction frac1, frac2;
cout << "Enter a fraction: ";
frac1.input();
frac1.output();
cout << "Enter a fraction: ";
frac2.input();
frac2.output();
frac1.plus_equal(frac1, frac2);
return 0;
}
```