#include <bits/stdc++.h>
using namespace std;
#define PB push_back
#define ZERO (1e-6)
#define INF int(1e9+1)
#define CL(A,I) (memset(A,I,sizeof(A)))
#define DEB printf("DEB!\n");
#define D(X) cout<<"  "<<#X": "<<X<<endl;
#define EQ(A,B) (A+ZERO>B&&A-ZERO<B)
typedef long long ll;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ii> vii;
#define IN(n) int n;scanf("%d",&n);
#define FOR(i, m, n) for (int i(m); i < n; i++)
#define F(n) FOR(i,0,n)
#define FF(n) FOR(j,0,n)
#define FT(m, n) FOR(k, m, n)
#define aa first
#define bb second
void ga(int N,int *A){F(N)scanf("%d",A+i);}
typedef long double ld;
double T,H,V,t,h,v,B,M,a;
bool ok(ld X){
    ld f=min((ld)B,V*(X-T)),W=max(ld(0),H-(X-T)*(X-T)/2),d=v*(X-t);
    if(sqrt(2*W/3)>X-t)return 0;
    if(W>h||d<f)return 0;
    M=X+f/v;
    return 1;
}
ld bs(ld B=0,ld E=INF){
    ld M;
    while(!EQ(B,E))
        if(ok(M=(B+E)/2))E=M;
        else B=M;
    return B;
}
int main(void){
    scanf("%lf%lf%lf%lf%lf%lf",&T,&V,&H,&t,&v,&h);
    B=sqrt(2*H)*V;
    a=bs(max(t,T),1e10);
    ok(a+ZERO);
    printf("%.8lf\n",M);
    return 0;
}