#include <stdio.h>

double menu_disp()
{
	printf("==========< ¸Þ´º >==========\n");
	printf("1. µ¡¼À(addtion)\n");
	printf("2. »¬¼À(subtraction)\n");
	printf("3. °ö¼À(multiplication)\n");
	printf("4. ³ª´°¼À(division)\n");
	printf(">>¿øÇÏ´Â ¸Þ´º¸¦ ¼±ÅÃÇϼ¼¿ä\n");

	return 0;
}

void res_dis(double a)
{
	printf("°á°ú°ªÀº %lfÀÔ´Ï´Ù\n",a);
}

void div(int menu)
{
	double inputA, inputB, temp, ok=1;
	while(ok==1)
	{
	printf("µÎ °³ÀÇ ¼ýÀÚ¸¦ ÀÔ·ÂÇϼ¼¿ä : ");
	scanf("%lf%lf",&inputA,&inputB);
	if (menu==4&&inputB==0) printf("ºÐ¸ð¿£ 0ÀÌ ¿Ã ¼ö ¾ø½À´Ï´Ù.\n");
	else ok=0;
	}
	switch(menu)
	{
		case 1:
			temp=inputA+inputB;
			break;
		case 2:
			temp=inputA-inputB;
			break;
		case 3:
			temp=inputA*inputB;
			break;
		case 4:
			temp=inputA/inputB;
			break;
	}
	res_dis(temp);
}

int main()
{
	int menu;

	menu_disp();
	scanf("%d",&menu);

	div(menu);

	return 0;
}