/* 5017 */

 #include <cstdio>

 #include <cstring>

 #include <cstdlib>

 #include <cmath>

 #define INF 1e30

 const double eps = 1e-;

 const double next = 0.99;

 int dir[][] = {

     {-, }, {, }, {, -}, {, },

     {-, }, {-, -}, {, -}, {, }

 };

 double a, b, c, d, e, f;

 double Length(double x, double y, double z) {

     return sqrt(x*x + y*y + z*z);

 }

 double getZ(double x, double y) {

     double A, B, C, delta, tmp;

     double z1, z2;

     A = c;

     B = d*y + e*x;

     C = a*x*x + b*y*y + f*x*y - 1.0;

     tmp = B*B - *A*C;

     if (tmp < )

         return INF;

     delta = sqrt(tmp);

     z1 = (-B+delta)/(2.0*A);

     z2 = (-B-delta)/(2.0*A);

     return fabs(z1) < fabs(z2) ? z1:z2;

 }

 int main() {

     double x, y, z;

     double xx, yy, zz;

     double step, tmp, ans;

     int i;

     #ifndef ONLINE_JUDGE

         freopen("data.in", "r", stdin);

         freopen("data.out", "w", stdout);

     #endif

     while (scanf("%lf%lf%lf%lf%lf%lf",&a,&b,&c,&d,&e,&f) != EOF) {

         x = ;

         y = ;

         z = getZ(x, y);

         ans = Length(x, y, z);

         step = .;

         while (step > eps) {

             for (i=; i<; ++i) {

                 xx = x + dir[i][]*step;

                 yy = y + dir[i][]*step;

                 zz = getZ(xx, yy);

                 if (zz >= INF)

                     continue;

                 tmp = Length(xx, yy, zz);

                 if (tmp < ans) {

                     x = xx;

                     y = yy;

                     z = zz;

                     ans = tmp;

                 }

             }

             step *= next;

         }

         printf("%.7lf\n", ans);

     }

     return ;

 }