#include <bits/stdc++.h>
using namespace std;

using db=long double;
const db eps=1e-9;
struct Vec
{
	db x,y;
	Vec(db a=0,db b=0) {x=a,y=b;}
	db norm() {return x*x+y*y;}
	db abs() {return sqrt(x*x+y*y);}
};
Vec operator + (Vec x,Vec y) {return Vec(x.x+y.x,x.y+y.y);}
Vec operator - (Vec x,Vec y) {return Vec(x.x-y.x,x.y-y.y);}
Vec operator * (Vec x,db y) {return Vec(x.x*y,x.y*y);}
Vec operator / (Vec x,db y) {return Vec(x.x/y,x.y/y);}
db cross(Vec x,Vec y) {return x.x*y.y-x.y*y.x;}
int sgn(db x)
{
	if(x<-eps) return -1;
	else if(x>eps) return 1;
	else return 0;
}
int ccw(Vec x,Vec y,Vec z) {return sgn(cross(y-x,z-x));}
struct Seg
{
	Vec s,t;
	Seg(Vec a=0,Vec b=0) {s=a,t=b;}
	Seg() {}
};
int isintersect(Seg p,Seg q)
{
	if(max(p.s.x,p.t.x)<min(q.s.x,q.t.x)) return 0;
	if(max(q.s.x,q.t.x)<min(p.s.x,p.t.x)) return 0;
	if(max(p.s.y,p.t.y)<min(q.s.y,q.t.y)) return 0;
	if(max(q.s.y,q.t.y)<min(p.s.y,p.t.y)) return 0;
	if(ccw(q.s,p.s,p.t)*ccw(q.t,p.s,p.t)==1) return 0;
	if(ccw(p.s,q.s,q.t)*ccw(p.t,q.s,q.t)==1) return 0;
	return 1;
}
Vec r90(Vec x) {return Vec(-x.y,x.x);}
Vec a[10],b[10];
const db pi=acos(-1);
db dif(db x,db y)
{
	db v=x-y;
	while(v>=2*pi) v-=2*pi;
	while(v<0) v+=2*pi;
	if(v<pi) return v;
	else return 2*pi-v;
}
void print(Vec x) {printf("%.2Lf %.2Lf\n",x.x,x.y);}
int ok1[10],ok2[10];
int main() {
#ifdef xay5421
	freopen("b.in","r",stdin);
#endif
	Vec a1,b1,a2,b2; db h1,h2;
	cin>>a1.x>>a1.y>>b1.x>>b1.y>>h1;
	cin>>a2.x>>a2.y>>b2.x>>b2.y>>h2;
	a[0]=a1,a[1]=b1,a[2]=b1+r90(b1-a1),a[3]=a1+r90(b1-a1);
	b[0]=a2,b[1]=b2,b[2]=b2+r90(b2-a2),b[3]=a2+r90(b2-a2);
	a[4]=a[0],b[4]=b[0];
	
	// print(a[0]),print(a[1]),print(a[2]),print(a[3]);
	// print(b[0]),print(b[1]),print(b[2]),print(b[3]);
	db ans=1e100;
	Vec ca=(a[0]+a[2])/2,cb=(b[0]+b[2])/2;
	db La=(ca.x-a[0].x)*(ca.x-a[0].x)+(ca.y-a[0].y)*(ca.y-a[0].y)+h1*h1;
	db Lb=(cb.x-b[0].x)*(cb.x-b[0].x)+(cb.y-b[0].y)*(cb.y-b[0].y)+h2*h2;
	// cout<<sqrt(Lb)<<endl;
	db lena=sqrt(La-(a[1]-a[0]).norm()/4),lenb=sqrt(Lb-(b[1]-b[0]).norm()/4);
	// cout<<lena<<" "<<lenb<<endl;
	for(int i=0;i<4;i++)
	{
		if(isintersect(Seg(ca,cb),Seg(a[i],a[i+1]))) ok1[i]=ok1[(i+1)%4]=ok1[(i+3)%4]=1;
		if(isintersect(Seg(ca,cb),Seg(b[i],b[i+1]))) ok2[i]=ok2[(i+1)%4]=ok2[(i+3)%4]=1;
	}
	for(int i=0;i<4;i++) if(ok1[i]) for(int j=0;j<4;j++) if(ok2[j])
	{
		Vec da=r90(a[i+1]-a[i]); da=da/da.abs(); da=da*lena;
		Vec va=(a[i+1]+a[i])/2+da;
		Vec db=r90(b[j+1]-b[j]); db=db/db.abs(); db=db*lenb;
		Vec vb=(b[j+1]+b[j])/2+db;
		// printf("%d %d : \n",i,j),print(va),print(vb);
		// printf("%d %d %d %d\n",ccw(va,a[i],vb),ccw(va,vb,a[i+1]),ccw(vb,b[j],va),ccw(vb,va,b[j+1]));
		if(!isintersect(Seg(va,vb),Seg(a[i],a[i+1]))) continue;
		if(!isintersect(Seg(va,vb),Seg(b[j],b[j+1]))) continue;
		if(ccw(va,a[i],vb)>=0&&ccw(va,vb,a[i+1])>=0)
		{
			if(ccw(vb,b[j],va)>=0&&ccw(vb,va,b[j+1])>=0)
			{
				ans=min(ans,(va-vb).abs());
			}
		}
	}
	auto chka=[&](int id,Vec v)
	{
		return ccw(a[id],a[(id+3)%4],v)<=0&&ccw(a[id],v,a[(id+1)%4])<=0;
	};
	auto chkb=[&](int id,Vec v)
	{
		return ccw(b[id],b[(id+3)%4],v)<=0&&ccw(b[id],v,b[(id+1)%4])<=0;
	};
	for(int i=0;i<4;i++) for(int j=0;j<4;j++)
	{
		if(chka(i,b[j])) continue;
		if(chkb(j,a[i])) continue;
		db l=sqrt(La)+sqrt(Lb)+(a[i]-b[j]).abs();
		ans=min(ans,l);
	}
	for(int i=0;i<4;i++) if(ok1[i]) for(int j=0;j<4;j++)
	{
		Vec da=r90(a[i+1]-a[i]); da=da/da.abs(); da=da*lena;
		Vec va=(a[i+1]+a[i])/2+da;
		if(chkb(j,va)) continue;
		if(!isintersect(Seg(va,b[j]),Seg(a[i],a[i+1]))) continue;
		if(ccw(va,a[i],b[j])>=0&&ccw(va,b[j],a[i+1])>=0)
		{
			db tl=sqrt(Lb)+(va-b[j]).abs();
			ans=min(ans,tl);
		}
	}
	for(int i=0;i<4;i++) for(int j=0;j<4;j++) if(ok2[j])
	{
		Vec db=r90(b[j+1]-b[j]); db=db/db.abs(); db=db*lenb;
		Vec vb=(b[j+1]+b[j])/2+db;
		if(chka(i,vb)) continue;
		if(!isintersect(Seg(a[i],vb),Seg(b[j],b[j+1]))) continue;
		if(ccw(vb,b[j],a[i])>=0&&ccw(vb,a[i],b[j+1])>=0)
		{
			long double tl=sqrt(La)+(vb-a[i]).abs();
			ans=min(ans,tl);
		}
	}
	printf("%.10Lf\n",ans);
	return 0;
}
/*
6.40312 44.0028
0 0 : 
5.00 6.40
8.09 63.91
-1 -1 -1 1
0 1 : 
5.00 6.40
-11.91 25.09
-1 1 -1 1
0 2 : 
5.00 6.40
26.91 5.09
1 -1 1 -1
0 3 : 
5.00 6.40
46.91 43.91
1 -1 1 -1
1 0 : 
3.60 5.00
8.09 63.91
1 -1 -1 1
1 1 : 
3.60 5.00
-11.91 25.09
1 -1 -1 1
1 2 : 
3.60 5.00
26.91 5.09
1 1 1 -1
1 3 : 
3.60 5.00
46.91 43.91
1 -1 1 -1
2 0 : 
5.00 3.60
8.09 63.91
1 1 -1 1
2 1 : 
5.00 3.60
-11.91 25.09
1 -1 -1 1
2 2 : 
5.00 3.60
26.91 5.09
-1 1 1 -1
2 3 : 
5.00 3.60
46.91 43.91
-1 1 1 -1
3 0 : 
6.40 5.00
8.09 63.91
-1 1 -1 1
3 1 : 
6.40 5.00
-11.91 25.09
-1 1 -1 1
3 2 : 
6.40 5.00
26.91 5.09
-1 -1 1 -1
3 3 : 
6.40 5.00
46.91 43.91
-1 1 1 -1
*/