#include <stdio.h>

struct complex{
    int real;
    int imag;
};//結(jié)構(gòu)體定義：分為實部和虛部

struct complex multiply(struct complex x, struct complex y);
//函數(shù)聲明
int main()
{
    struct complex product, x, y;

    scanf("%d%d%d%d", &x.real, &x.imag, &y.real, &y.imag);//輸入倆實部和虛部
    product = multiply(x, y);//使用函數(shù)返回復數(shù)計算的結(jié)果
    printf("(%d+%di) * (%d+%di) = %d + %di\n", 
            x.real, x.imag, y.real, y.imag, product.real, product.imag);
    
    return 0;
}

struct complex multiply(struct complex x, struct complex y){
    struct complex res;
    res.real=x.real*y.real-x.imag*y.imag;
    res.imag=x.real*y.imag+x.imag*y.real;
    return res;
}

#include <stdio.h>
#include <math.h>

struct point {
    double x, y, z;
};

void read_point(struct point *p);
double distance(struct point a, struct point b);

int main(void)
{
    struct point p1, p2;

    read_point(&p1);
    read_point(&p2);

    printf("%f\n", distance(p1, p2));

    return 0;
}

void read_point(struct point *p)
{
    scanf("%lf %lf %lf", &p->x, &p->y, &p->z);
}

//  計算并返回平面上兩點 a 和 b 之間的歐氏距離
double distance(struct point a, struct point b){
    double res;
    res=pow((a.x-b.x),2)+pow((a.y-b.y),2)+pow((a.z-b.z),2);
    res=sqrt(res);
    return res;
}