#include <iostream>
#include <cmath>
using namespace std;
int main() {
    int T, M;
    cin >> T >> M;
    while (T--) {
        double a, b, c;
        cin >> a >> b >> c;
        double t = b * b - 4 * a * c;
        if (t < 0) {
            cout << "NO" << endl;
            continue;
        }
        double a1 = (-b - sqrt(t)) / 2 / a, a2 = (-b + sqrt(t)) / 2 / a;
        cout << max(a1, a2) << endl;
    }
    return 0;
}

这样写竟然得不到50分，会神奇的输出-0！