#include<bits/stdc++.h>
using namespace std;
#define int long long
#define double __float128
const double eps=1e-12;
struct ss{
    double x,y;
    double len()
    {
        return sqrtl(x*x+y*y);
    }
    double operator *(const ss ot)const{
        return x*ot.x+y*ot.y;
    }
    ss operator -(const ss ot)const{
        return (ss){x-ot.x,y-ot.y};
    }
    ss operator +(const ss ot)const{
        return (ss){x+ot.x,y+ot.y};
    }
    ss operator *(const double ot)const{
        return (ss){x*ot,y*ot};
    }
}a[4],b[4];
double mul(ss A,ss B)
{
    return A.x*B.y-A.y*B.x;
}
double dis(ss E,ss a,ss b)
{
    return fabsl(mul(E,a-b)/(a-b).len());
}
bool check(ss A,ss B,ss C,ss D)
{
    double l=min(A.x,B.x),r=max(A.x,B.x);
    double L=min(C.x,D.x),R=max(C.x,D.x);
    if(r+eps<L||R+eps<l)return 0;
    l=min(A.y,B.y),r=max(A.y,B.y);
    L=min(C.y,D.y),R=max(C.y,D.y);
    if(r+eps<L||R+eps<l)return 0;
    if(mul(B-A,C-A)*mul(B-A,D-A)>eps)
        return 0;
    if(mul(D-C,A-C)*mul(D-C,B-C)>eps)
        return 0;
    return 1;
}
void sol()
{
    int x1,y1,x2,y2,h1,h2;
    cin>>x1>>y1>>x2>>y2>>h1;
    a[0]=(ss){x1,y1};
    a[1]=(ss){x2,y2};
    ss p=a[1]-a[0];
    a[2]=(ss){a[1].x-p.y,a[1].y+p.x};
    a[3]=(ss){a[2].x-p.x,a[2].y-p.y};
    cin>>x1>>y1>>x2>>y2>>h2;
    b[0]=(ss){x1,y1};
    b[1]=(ss){x2,y2};
    p=b[1]-b[0];
    b[2]=(ss){b[1].x-p.y,b[1].y+p.x};
    b[3]=(ss){b[2].x-p.x,b[2].y-p.y};
    //cout<<(float)b[3].x<<" "<<(float)b[3].y<<endl;
    ss m1=(ss){(a[0].x+a[2].x)/2,(a[0].y+a[2].y)/2};
    ss m2=(ss){(b[0].x+b[2].x)/2,(b[0].y+b[2].y)/2};
    double d1=mul(m1-a[0],a[1]-a[0])/(a[1]-a[0]).len();
    double d2=mul(m2-b[0],b[1]-b[0])/(b[1]-b[0]).len();
    double len1=sqrtl(h1*h1+d1*d1);
    double llen1=sqrtl(h1*h1+(m1-a[0]).len()*(m1-a[0]).len());
    //cerr<<len1<<'\n';
    double len2=sqrtl(h2*h2+d2*d2);
    double llen2=sqrtl(h2*h2+(m2-b[0]).len()*(m2-b[0]).len());
    //cerr<<(float)len2<<'\n';
    double ans=1e18;
    for(int i=0;i<4;i++)
    {
        ss mm1=(ss){(a[i].x+a[(i+1)%4].x)/2,(a[i].y+a[(i+1)%4].y)/2};
        ss p1=m1-mm1;
        ss E=mm1+p1*(len1/p1.len());
        //cerr<<(float)len1<<" "<<(float)p1.len()<<endl;
        for(int j=0;j<4;j++)
        {
            ss mm2=(ss){(b[j].x+b[(j+1)%4].x)/2,(b[j].y+b[(j+1)%4].y)/2};
            ss p2=m2-mm2;
            ss F=mm2+p2*(len2/p2.len());
            //cout<<(float)E.x<<" "<<(float)E.y<<" "<<(float)F.x<<" "<<(float)F.y<<" "<<(float)b[j].x<<" "<<(float)b[j].y<<" "<<(float)b[(j+1)%4].x<<" "<<(float)b[(j+1)%4].y<<endl;
            if(check(b[j],b[(j+1)%4],E,F)&&check(a[i],a[(i+1)%4],E,F))
            {
                //cout<<(float)E.x<<" "<<(float)E.y<<" "<<(float)F.x<<" "<<(float)F.y<<" "<<i<<" "<<j<<" "<<(float)b[j].x<<" "<<(float)b[j].y<<endl;
                if((E-F).len()>len1+len2)
                    ans=min(ans,(E-F).len());
            }
            if(check(b[j],b[(j+1)%4],a[i],F))
            {
                ans=min(ans,(a[i]-F).len()+llen1);
            }
            if(check(a[i],a[(i+1)%4],b[j],E))
            {
                ans=min(ans,(b[j]-E).len()+llen2);
            }
            ans=min(ans,(a[i]-b[j]).len()+llen1+llen2);
        }
    }
    #undef double
    cout<<fixed<<setprecision(9)<<(long double)ans<<'\n';
}
signed main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    sol();
}
/*
0 0 10 0 4
9 18 34 26 42
5 3.31662 21.5 67.5391 9 26 34 26 1
5 3.31662 21.5 67.5391 9 26 34 26 1
5 3.31662 21.5 67.5391 9 26 34 26 1
5 3.31662 21.5 67.5391 9 26 34 26 1
6.68338 5 -7.53914 38.5 34 26 34 51 0
6.68338 5 -7.53914 38.5 34 26 34 51 0
6.68338 5 -7.53914 38.5 34 26 34 51 0
6.68338 5 -7.53914 38.5 34 26 34 51 0
5 6.68338 21.5 9.46086 34 51 9 51 0
5 6.68338 21.5 9.46086 34 51 9 51 0
5 6.68338 21.5 9.46086 34 51 9 51 0
5 6.68338 21.5 9.46086 34 51 9 51 0
3.31662 5 50.5391 38.5 9 51 9 26 0
3.31662 5 50.5391 38.5 9 51 9 26 0
3.31662 5 50.5391 38.5 9 51 9 26 0
3.31662 5 50.5391 38.5 9 51 9 26 0
*/