#include <iostream>
#include <fstream>
#include <math.h>

using namespace std;

double tf, vf, hf, td, vd, hd;

int main() {
    cin >> tf;
    cin >> vf;
    cin >> hf;
    cin >> td;
    cin >> vd;
    cin >> hd;

    double res;

    double s = sqrt((hf - hd)* 2) * vf;
    //cout << "s: "<< s << endl;

    double sdm = sqrt((2* hd) /3)* vd;
    //cout << "sdm: "<< sdm << endl;

    if(s < sdm) {
        double a = 3/ (2 * vd* vd) - 1/ (2* vf *vf);
        //cout << "a: "<< a << endl;

        double vj = sqrt(2*hd*3);
        //cout << "vj: "<< vj << endl;

        double b = -vj / vd;
        //cout << "b: "<< b << endl;

        double s1 = (-b + sqrt(b*b - 4*a*hf)) / (2*a);
        double s2 = (-b - sqrt(b*b - 4*a*hf)) / (2*a);
        //cout << "s1: "<< s1 << endl;
        //cout << "s2: "<< s2 << endl;

        if(s1 < 0) s = s2;
        else if(s2 < 0) s = s1;
        else if(s1 < s2) s = s1;
        else s = s2;
        //cout << "s: "<< s << endl;
    }
    double tle = sqrt(2*hf);
    //cout << "tle: "<< tle << endl;

    if(vd <= vf) {
        res = 2*tle*vf / vd +td;
    } else {
        double t = (tf*vf - td * vd) / (vf - vd);
        //cout << "t: "<< t << endl;
        if(t > tle) res = 2*tle*vf / vd +td;
        else if((t-td)*vd < s) res = tf + s/vf+s/vd;
        else res = (t- td)*2+td;
    }
    cout << res << endl;

    return 0;
}