#include <bits/stdc++.h>
using namespace std;
int main() {
  double a, b, c;
  while (scanf("%lf%lf%lf", &a, &b, &c) != EOF) {
    if (a == 0 && b != 0)
      printf("1\n%.10lf\n", -c / b);
    else if (a == 0 && b == 0)
      printf("-1\n");
    else if (a != 0) {
      double t = b * b - 4 * a * c;
      if (t > 0) {
        printf("2\n");
        printf("%.10lf\n", (-b - sqrt(t)) / (2 * a));
        printf("%.10lf\n", (-b + sqrt(t)) / (2 * a));
      } else if (t == 0) {
        printf("1\n");
        printf("%.10lf\n", (-b + sqrt(t)) / (2 * a));
      } else
        printf("-1\n");
    }
  }
}
