#include <iostream>

using namespace std;

class Complex {
    public:
        Complex(double, double);

        double getRe();
        double getIm();

        void setRe(double);
        void setIm(double);

        bool operator == (const Complex &);
        bool operator != (const Complex &);

        Complex operator + (const Complex &);
        Complex operator - (const Complex &);
        Complex operator * (const Complex &);
        Complex operator / (const Complex &);

        friend ostream & operator << (ostream & os,const Complex & a);
        friend istream & operator >> (istream & is, Complex & a);

    private:
        double re, im;
};

double Complex::getRe() {
    return re;
}
double Complex::getIm() {
    return im;
}

void Complex::setRe(double a) {
    re = a;
}
void Complex::setIm(double a) {
    im = a;
}

bool Complex::operator ==(const Complex & x) {
    return (re == x.re && im == x.im);
}

bool Complex::operator !=(const Complex & x) {
    return !(re == x.re && im == x.im);
}

Complex::Complex(double Re = 0.0, double Im = 0.0) {
    re = Re;
    im = Im;
}
Complex Complex::operator + (const Complex & x) {
    Complex res;
    res.re = re + x.re;
    res.im = im + x.im;
    return res;
}
Complex Complex::operator - (const Complex & x) {
    Complex res;
    res.re = re - x.re;
    res.im = im - x.im;
    return res;
}

Complex Complex::operator * (const Complex & x) {
    Complex res;
    res.re = re * x.re - im * x.im;
    res.im = re * x.im + x.re * im;
    return res;
}
Complex Complex::operator / (const Complex & x) {
    Complex res;
    res.re = (re * x.re + im * x.im) / (im * im + x.im * x.im);
    res.im = (im * x.re - re * x.im) / (im * im + x.im * x.im);
    return res;
}

ostream & operator << (ostream & os,const Complex & a) {
    os << a.re;
    if (a.im)
        os << showpos << a.im << noshowpos << "i";
    os << endl;
    return os;
}
istream & operator >> (istream & is, Complex & a) {
    is >> a.re >> a.im;
    return is;
}

int main() {
    Complex a, b;
    cin >> a;
    cin >> b;
    cout << a;
    a = a + b;
    cout << a;
    a = a / b;
    cout << a;
    a.setIm(5);
    a.setRe(2);
    b.setIm(5);
    b.setRe(2);
    if (a!=b) cout << "NO";
    else cout <<"YES";
    b = b * a;
    cout << b;
    b = b / a;
    if (a==b) cout << "YES";
    else cout <<"NO";
    cout << endl << a.getRe() << " " << a.getIm() << endl;
}