#include <stdio.h>
#include <stdlib.h>
struct Zespolone
{
  int re;
  int im;
};

void suma(struct Zespolone a, struct Zespolone b);
void roznica(struct Zespolone a, struct Zespolone b);
void iloczyn(struct Zespolone a,struct Zespolone b);
void iloraz(struct Zespolone a,struct Zespolone b);
struct Zespolone* suma_wsk(struct Zespolone a, struct Zespolone b);
struct Zespolone* roznica_wsk(struct Zespolone a,struct Zespolone b);
struct Zespolone* iloczyn_wsk(struct Zespolone a,struct Zespolone b);
struct Zespolone* iloraz_wsk(struct Zespolone a,struct Zespolone b);
int main()
{
    struct Zespolone cp1,cp2;
    scanf("%d %d %d %d",&cp1.re,&cp1.im,&cp2.re,&cp2.im);

}
void suma(struct Zespolone a, struct Zespolone b)
{
    a.re += b.re;
    a.im += b.im;
}
void roznica(struct Zespolone a, struct Zespolone b)
{
    a.re -= b.re;
    a.im -= b.im;
}
void iloczyn(struct Zespolone a, struct Zespolone b)
{
    int temp_hld=a.re;
    a.re = a.re*b.re - a.im*b.im;
    a.im = temp_hld*b.im + a.im*b.re;
}
void iloraz(struct Zespolone a,struct Zespolone b)
{
    if (b.re == 0 && b.im == 0) printf("ERROR! Division by zero.\n");
    else
    {
        a.re = (a.re*b.re + a.im*b.im)/(b.re*b.re + b.im*b.im);
        a.im = (a.im*b.re - a.re*b.im)/(b.re*b.re + b.im*b.im);
    }
}
struct Zespolone* suma_wsk(struct Zespolone a,struct Zespolone b)
{
    struct Zespolone c;
    c.re += b.re;
    c.im += b.im;
    struct Zespolone* wsk;
    wsk=&c;
    return wsk;
}
struct Zespolone* roznica_wsk(struct Zespolone a,struct Zespolone b)
{
    c.re -= b.re;
    c.im -= b.im;
    Zespolone* wsk;
    wsk=&c;
    return wsk;
}
struct Zespolone* iloczyn_wsk(struct Zespolone a,struct Zespolone b)
{
    struct Zespolone c;
    c.re = a.re*b.re - a.im*b.im;
    c.im = a.re*b.im + a.im*b.re;
    struct Zespolone* wsk;
    wsk=&c;
    return wsk;
}
struct Zespolone* iloraz_wsk(struct Zespolone a,struct Zespolone b)
{
    struct Zespolone c;wk
    if (b.re == 0 && b.im == 0) printf("ERROR! Division by zero.\n");
    else
    {
        c.re = (a.re*b.re + a.im*b.im)/(b.re*b.re + b.im*b.im);
        c.im = (a.im*b.re - a.re*b.im)/(b.re*b.re + b.im*b.im);
    }
    struct Zespolone* wsk;
    wsk=&c;
    return wsk;
}