题目链接：点击打开链接

#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <iostream>
#include <map>
#include <set>
#include <math.h>
using namespace std;
#define inf 10000000
#define ll __int64
#define N 2005
ll a,b,c;
int main(){
	ll i, j;
	while(cin>>a>>b>>c) {
		double A = (double)a, B = (double)b, C = (double)c;
		if(a==0) {
			if(b==0) {
				if(c==0)puts("-1");
				else puts("0");
				continue;
			}
			puts("1");
			printf("%.10lf\n", (-C)/B);
			continue;
		}
		ll h = b*b-4*a*c;		
		if(h<0){puts("0");continue;}
		if(h==0) {
			puts("1");
			printf("%.10lf\n",-(B/(2.0*A)));
		}
		else {
			puts("2");
			double H = sqrt((double)h);
			if((-B-H)/(2.0*A) > (-B+H)/(2.0*A))
				H *= -1;
			printf("%.10lf\n%.10lf\n", (-B-H)/(2.0*A), (-B+H)/(2.0*A));
		}
	}
	return 0;
}