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

int QuadFormula(double a, double b, double c){
	double D = (b*b - 4*a*c);
	double x1, x2, x3 ,x4;
	x1 = ((-b + sqrt(D)) / (2*a));
	x2 = ((-b - sqrt(D)) / (2*a));
	x3 = (-b /(2*a));
	x4 = (sqrt(-D) / (2*a));
	if(a == 0){
		printf("計算できません。");
	}else if(D > 0){
		printf("解は%lf,%lfです。\n",x1,x2);
	}else if(D == 0){
		printf("解は%lfです。\n",x1);
	}else{
	    printf("解は%lf+i%lf,%lf-i%lfです。\n",x3,x4,x3,x4);
    }
    return 0;
}
int main(void) {
	 double a, b, c;
	 printf("aの値:\n");
	 scanf("%lf",&a);
	 printf("bの値:\n");
	 scanf("%lf",&b);
	 printf("cの値:\n");
	 scanf("%lf",&c);
	 
	 QuadFormula(a,b,c);
return 0;
}