#include<cmath>
using namespace std;
const int N=1000;
int a[N],b[N],c[N];
inline int gcd(int a,int b)
{
    if (b==0)
        return a;
    else
        return gcd(b,a%b);
}
int main()
{
    int n,t;
    cin>>n>>t;
    for(int i=1;i<=n;i++)
    {
        cin>>a[i]>>b[i]>>c[i];
    }
    for(int i=1;i<=n;i++)
    {
        int delta=b[i]*b[i]-4*a[i]*c[i];
        if(delta<0)
            cout<<"NO"<<endl;
            else if(delta==0)
            {
                cout<<-b[i]/2*a[i]<<endl;
            }
            else
                cout<<-b[i]+sqrt(delta)/(2*a[i])<<endl;
    }
}
  //想先把c过掉，结果一直10pts