#includ <stdio.h>
#includ <math.h>

int main()
{
   double a, b, c, d, x1, x2;

   scanf("%d", &a);
   scanf("%d", &b);
   scanf("%d", &c);

   d = b * b - 4 * a * c;

   if (0 > d)
   {
      return ー1;
   }