// 解一元二次方程式：ax^2 + bx + c  = 0 輸入a, b, c 利用公式解解x
#include <iostream>
#include <math.h>
using namespace std;
int main ()
{
double a, b, c;
cout << "ax^2 + bx + c  = 0\n請依序輸入a, b, c\n";
cin >> a >> b >> c;
cout << "答案是";
if(pow(b, 2) - 4 * a * c > 0)
cout << ((-1) * b + sqrt(pow(b, 2) - 4 * a * c)) / 2 / a << " " <<
        (-b - sqrt(pow(b, 2) - 4 * a * c)) / 2 / a << endl;
else if(pow(b, 2) - 4 * a * c == 0)
cout << (-1) * b / 2 / a << endl;
else
cout << "無解\n";
return 0;
}