#include <stdio.h>
#include <vector>
#include <iostream>
#include <stdlib.h>
#include <string>
#include <string.h>
#include <set>
#include <algorithm>
#include <math.h>

#define EPS 1e-10
using namespace std;

double solve(double t, int tr, int tg)
{
    int t1 = (int) (t + EPS);
    int k = t1 / (tr + tg);
    int tmin = k * (tr + tg) + tr;
    int tmax = (k + 1) * (tr + tg);
    if (t > tmin - EPS && t < tmax + EPS) return t;
    if (t < tmin - tr + EPS) return tmin - tr;
    if (t < tmin - EPS) return tmin;
    return tmin + (tr + tg);
}

int main(void)
{
    freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);

    double l, vmin, vmax, amin, amax;
    double s;
    int tr, tg;

    cin >> l >> vmin >> vmax >> amin >> amax;
    cin >> s >> tr >> tg;

    double ts = sqrt(2 * s / amax);
    double tvmax = vmax / amax;

    double tans, vans;
    if (tvmax < ts)
    {
        tans = tvmax;
        s -= tvmax * tvmax * amax / 2;
        tans += s / vmax;
        vans = vmax;
        tans = solve(tans, tr, tg);
    }
    else
    {
        ts = solve(ts, tr, tg);

        double tvmin = vmin / amin;
        double triptvmin = tvmin * (vmin) / 2;
        double ll = 0, rr = ts;
        for (int i = 0; i < 1000; i++)
        {
            double tt = (rr + ll) / 2;
            double xcur, vcur;
            if (tt > tvmin)
            {
                vcur = vmin;
                xcur = triptvmin + vmin * (tt - tvmin);
            }
            else
            {
                xcur = amin * tt * tt / 2;
                vcur = amin * tt;
            }

            double tost = ts - tt;
            double ss = s - xcur;
            double tss;
            if ((-vcur - sqrt(2*amax*s + vcur*vcur))/amax >= 0) tss = (-vcur - sqrt(2*amax*s + vcur*vcur))/amax; else
                tss = (-vcur + sqrt(2*amax*s + vcur*vcur))/amax;
            double tvmaxss = (vmax - vcur) / amax;

            double tres;
            if (tvmaxss < tss)
            {
                tres = tvmaxss;
                tres += (ss - tvmaxss * (vmax + vcur) / 2) / vmax;
            }
            else
            {
                tres = tss;
            }

            if (tres + tt < ts) ll = tt; else rr = tt;
        }


        {
            double tt = (rr + ll) / 2;
            double xcur, vcur;
            if (tt > tvmin)
            {
                vcur = vmin;
                xcur = triptvmin + vmin * (tt - tvmin);
            }
            else
            {
                xcur = amin * tt * tt / 2;
                vcur = amin * tt;
            }

            double tost = ts - tt;
            tans = ts;
            vans = vcur + amax * tost;
        }
    }

    tvmax = (vmax - vans) / amax;
    l-= s;
    if ((-vans - sqrt(2 * amax * l + vans*vans))/amax >= 0) ts = (-vans - sqrt(2 * amax * l + vans*vans))/amax ; else
    ts = (-vans + sqrt(2 * amax * l + vans*vans))/amax;
    if (tvmax < ts)
    {
        tans += tvmax;
        l -= tvmax * (vmax + vans) / 2;
        tans += l / vmax;
    }
    else
    {
        tans += ts;
    }

    printf("%.10lf", tans);
    return 0;
}