Complex operator+(const Complex& c1, const Complex& c2) {
    Complex result;
    result.a = c1.a + c2.a; // Sum of real parts
    result.b = c1.b + c2.b; // Sum of imaginary parts
    return result;
}

std::ostream& operator<<(std::ostream& os, const Complex& c) {
    os << c.a << "+i" << c.b;
    return os;
}