#include <cstdio>#include <algorithm>#include <cstring>#include <cmath>using namespace std;const double eps = 1e-8;const double r = 0.99;	//降温速度const int dx[] = { 0, 0, 1, -1, 1, -1, 1, -1 };const int dy[] = { 1, -1, 0, 0, -1, 1, 1, -1 };double a, b, c, d, e, f;double dis(double x, double y, double z) {	return sqrt(x * x + y * y + z * z);}//已知x,y,求zdouble getz(double x, double y) {	double A = c, B = e * x + d * y,		C = a * x * x + b * y * y + f * x * y - 1;	double delta = B * B - 4 * A * C;	if (delta < 0) return 1e60;	double z1 = (-B + sqrt(delta)) / 2 / A,		z2 = (-B - sqrt(delta)) / 2 / A;	if (z1 * z1 < z2 * z2) return z1;	else return z2;}double solve() {	//模拟退火	double step = 1;	//步长	double x = 0, y = 0, z;	while (step > eps) {		z = getz(x, y);		for (int i = 0; i < 8; i++) {			double nx = x + dx[i] * step,				ny = y + dy[i] * step,				nz = getz(nx, ny);			if (nz > 1e30) continue;			if (dis(nx, ny, nz) < dis(x, y, z)) {				x = nx; y = ny; z = nz;			}		}		step *= r;	}	return dis(x, y, z);}int main() {	while (scanf("%lf%lf%lf%lf%lf%lf", &a, &b, &c, &d, &e, &f) != EOF) {		printf("%.8f\n", solve());	}	return 0;}