#include <stdio.h>
int main()
{
	int button; double value1, value2;
	while(1)
	{
		char *sel;
		printf("\n계산기\n1.더하기\n2.빼기\n3.곱하기\n4.나누기\n5.나가기\n");scanf("%d", &button);
		if (button==1)sel="더할"; else if (button==2) sel="뺄"; else if (button==3) sel="곱할";
		else if (button==4)sel="나눌"; else if (button==5) break;
		else {printf("다시 선택하시오"); continue;}
		printf("\n%s 두 값 입력:", sel); scanf("%lf %lf", &value1, &value2);
		printf("%.3lf%s%.3lf=%.3lf", value1,(button==1)?"+":(button==2)?"-":(button==3)?"*":
      (button==4)?"/":"?",value2, (button==1)?value1+value2:(button==2)?value1-value2:
			(button==3)?value1*value2:(button==4)?value1/value2:0);
		break;

	}
}