#include<bits/stdc++.h>
using namespace std;
int T,m;
double a,b,c,d;
int main(){
	cin>>T>>m;
	while(T--){
		cin>>a>>b>>c;
		d=b*b-4*a*c;
		if(d<0) cout<<"NO\n";
		else{
			cout<<max((-b+sqrt(d))/(2*a),(-b-sqrt(d))/(2*a))<<endl;
		}
	}
	return 0;
}

C 性质骗分