#include <stdio.h>
#include <math.h>

static double quad_zeros(double a, double b, double c, double d) {
    return (-b + d * sqrt(b * b - 4 * a * c)) / (2 * a);
}

int main() {
    double tf = 0, vf = 0, hf = 0, td = 0, vd = 0, hd = 0;
    scanf("%lf %lf %lf %lf %lf %lf", &tf, &vf, &hf, &td, &vd, &hd);
    double df = td - tf;
    double tj = sqrt(3 * hd / 2);
    double vj = sqrt(6 * hd);
    double t0f = sqrt(2 * hf);
    double xf = vf * t0f;
    double t0c = (xf / vd) + df;
    double t0d = (df * vd) / (vd - vf);
    if (t0d >= df && t0d < t0c) {
        double solv2 = quad_zeros(1, - (2 * df + vj), hf - df * df, -1);
        if (solv2 > tj) solv2 = tj;
        double t1 = solv2 + df;
        double t0 = (t0d < t1 ? t1 : t0d);
        double x1 = (t0 - tf) * vf;
        double t2 = x1 / vd;
        printf("%.8f\n", t0 + t2 + tf);
    }
    else {
        printf("%.8f\n", t0c + (xf / vd) + tf);
    }
    return 0;
}