#include<bits/stdc++.h>
#define mm(a,b) memset(a,b,sizeof(a))
#define ACCELERATE (ios::sync_with_stdio(false),cin.tie(0))
#define pii pair<int,int>
#define pdd pair<double,double>
#define pll pair<long long,long long>
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define rep(i,a,b) for(int i=(a);i<=(b);i++)
#define per(i,a,b) for(int i=(a);i>=(b);i--)
#define rush() int T;scanf("%d",&T);while(T--)
#define debug(x) cout<<#x<<": "<<x<<endl
#define sc(a) scanf("%d",&a)
#define sc2(a,b) scanf("%d%d",&a,&b)
#define sc3(a,b,c) scanf("%d%d%d",&a,&b,&c)
#define pf(x) printf("%d\n",x)
#define pf2(x,y) printf("%d %d\n",x,y)
#define pf3(x,y,z) printf("%d %d %d\n",x,y,z)
#define all(x) (x).begin(),(x).end()
#define PI acos(-1.0)
#define E exp(1.0)
#define db double
#define ll long long
#define ld long double
#define ull unsigned long long
//#define io
using namespace std;
const int inf=0x3f3f3f3f;
const ll INF=0x3f3f3f3f3f3f3f3f;
//#define gc getchar
//char buf[1<<21],*p1=buf,*p2=buf;
//inline int gc(){return p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++;}
//inline int read()
//{
//    int ret=0,f=0;char c=gc();
//    while(!isdigit(c)){if(c=='-')f=1;c=gc();}
//    while(isdigit(c)){ret=ret*10+c-48;c=gc();}
//    if(f)return -ret;return ret;
//}
const int N=1e2+5;
const db EPS=1e-10;
inline int sign(db a){return a<-EPS?-1:a>EPS;}
inline int cmp(db a,db b){return sign(a-b);}
inline db sqr(db x){return x*x;}
struct Point{
    db x,y;
    Point(){}
    Point(db _x,db _y):x(_x),y(_y){}
    void input(){scanf("%lf%lf",&x,&y);}
    void output(){printf("%.10f %.10f\n",x,y);}
    bool operator == (Point b)const{
        return sign(x-b.x)==0&&sign(y-b.y)==0;
    }
    bool operator < (Point b)const{
        return sign(x-b.x)==0?sign(y-b.y)<0:x<b.x;
    }
    Point operator + (const Point &b)const{
        return Point(x+b.x,y+b.y);
    }
    Point operator - (const Point &b)const{
        return Point(x-b.x,y-b.y);
    }
    db operator ^ (const Point &b)const{
        return x*b.y-y*b.x;
    }
    db operator * (const Point &b)const{
        return x*b.x+y*b.y;
    }
    db len(){return hypot(x,y);}
    db len2(){return x*x+y*y;}
    db distance(Point p){return hypot(x-p.x,y-p.y);}
    Point operator * (const db &k)const{
        return Point(x*k,y*k);
    }
    Point operator / (const db &k)const{
        return Point(x/k,y/k);
    }
    db rad(Point a,Point b){
        Point p=*this;
        return fabs(atan2(fabs((a-p)^(b-p)),(a-p)*(b-p)));
    }
    Point unit(){return *this/len();}
    Point trunc(db r){
        db l=len();
        if(!sign(l))return *this;
        r/=l;
        return Point(x*r,y*r);
    }
    Point rotleft(){return Point(-y,x);}
    Point rotright(){return Point(y,-x);}
    Point rotate(Point p,db angle){
        Point v=(*this)-p;
        db c=cos(angle),s=sin(angle);
        return Point(p.x+v.x*c-v.y*s,p.y+v.x*s+v.y*c);
    }
};
#define cross(p1,p2,p3) ((p2.x-p1.x)*(p3.y-p1.y)-(p3.x-p1.x)*(p2.y-p1.y))
#define crossOp(p1,p2,p3) sign(cross(p1,p2,p3))
struct Line{
    Point s,e;
    Line(){}
    Line(Point _s,Point _e):s(_s),e(_e){}
    bool operator == (Line v){
        return (s==v.s)&&(e==v.e);
    }
    Line(Point p,db angle){
        s=p;
        if(sign(angle-PI/2)==0)e=(s+Point(0,1));
        else e=(s+Point(1,tan(angle)));
    }
    Line(db a,db b,db c){
        if(sign(a)==0){
            s=Point(0,-c/b);e=Point(1,-c/b);
        }else if(sign(b)==0){
            s=Point(-c/a,0);e=Point(-c/a,1);
        }else{
            s=Point(0,-c/b);e=Point(1,(-c-a)/b);
        }
    }
    void input(){s.input();e.input();}
    void adjust(){if(e<s)swap(s,e);}
    db length(){return s.distance(e);}
    //[0,PI)
    db angle(){
        db k=atan2(e.y-s.y,e.x-s.x);
        if(sign(k)<0)k+=PI;
        if(sign(k-PI)==0)k-=PI;
        return k;
    }
    //line|1 on the left|2 on the right|3 on line|
    int relation(Point p){
        int c=sign((p-s)^(e-s));
        if(c<0)return 1;
        else if(c>0)return 2;
        else return 3;
    }
    bool pointonseg(Point p){
        return sign((p-s)^(e-s))==0&&sign((p-s)*(p-e))<=0;
    }
    bool parallel(Line v){
        return sign((e-s)^(v.e-v.s))==0;
    }
    //|0 not intersect|1 non-standard|2 intersect|
    int segcrossseg(Line v){
        int d1=sign((e-s)^(v.s-s));
        int d2=sign((e-s)^(v.e-s));
        int d3=sign((v.e-v.s)^(s-v.s));
        int d4=sign((v.e-v.s)^(e-v.s));
        if((d1^d2)==-2&&(d3^d4)==-2)return 2;
        return (d1==0&&sign((v.s-s)*(v.s-e))<=0)||
            (d2==0&&sign((v.e-s)*(v.e-e))<=0)||
            (d3==0&&sign((s-v.s)*(s-v.e))<=0)||
            (d4==0&&sign((e-v.s)*(e-v.e))<=0);
    }
    //|0 not intersect|1 non-standard|2 intersect|
    int linecrossseg(Line v){
        int d1=sign((e-s)^(v.s-s));
        int d2=sign((e-s)^(v.e-s));
        if((d1^d2)==-2)return 2;
        return (d1==0||d2==0);
    }
    //|0 parallel|1 coincides|2 intersect|
    int linecrossline(Line v){
        if((*this).parallel(v))return v.relation(s)==3;
        return 2;
    }
    //要保证两直线不平行或重合
    Point crosspoint(Line v){
        db a1=(v.e-v.s)^(s-v.s);
        db a2=(v.e-v.s)^(e-v.s);
        return Point((s.x*a2-e.x*a1)/(a2-a1),(s.y*a2-e.y*a1)/(a2-a1));
    }
    db dispointtoline(Point p){
        return fabs((p-s)^(e-s))/length();
    }
    db dispointtoseg(Point p){
        if(sign((p-s)*(e-s))<0||sign((p-e)*(s-e))<0)return min(p.distance(s),p.distance(e));
        return dispointtoline(p);
    }
    //前提是两线段不相交，相交距离就是0了
    db dissegtoseg(Line v){
        return min(min(dispointtoseg(v.s),dispointtoseg(v.e)),min(v.dispointtoseg(s),v.dispointtoseg(e)));
    }
    Point lineprog(Point p){
		return s + ( ((e-s)*((e-s)*(p-s)))/((e-s).len2()) );
	}
	Point symmetrypoint(Point p){
		Point q = lineprog(p);
		return Point(2*q.x-p.x,2*q.y-p.y);
	}
};
struct circle{
    Point p;
    db r;
    circle(){}
    circle(Point _p,db _r):p(_p),r(_r){}
    circle(db _x,db _y,db _r){
        p=Point(_x,_y);r=_r;
    }
    //三角形的外接圆
    circle(Point a,Point b,Point c){
        Line u=Line((a+b)/2,((a+b)/2)+((b-a).rotleft()));
        Line v=Line((b+c)/2,((b+c)/2)+((c-b).rotleft()));
        p=u.crosspoint(v);
        r=p.distance(a);
    }
    //三角形的内切圆
    circle(Point a,Point b,Point c,bool t){
        Line u,v;
        db m=atan2(b.y-a.y,b.x-a.x),n=atan2(c.y-a.y,c.x-a.x);
        u.s=a;
        u.e=u.s+Point(cos((n+m)/2),sin((n+m)/2));
        m=atan2(a.y-b.y,a.x-b.x),n=atan2(c.y-b.y,c.x-b.x);
        v.s=b;
        v.e=v.s+Point(cos((n+m)/2),sin((n+m)/2));
        p=u.crosspoint(v);
        r=Line(a,b).dispointtoseg(p);
    }
    void input(){
        p.input();
        scanf("%lf",&r);
    }
    void output(){
        printf("%2.f %.2f %.2f\n",p.x,p.y,p,r);
    }
    bool operator == (circle v){
        return (p==v.p)&&sign(r-v.r)==0;
    }
    bool operator < (circle v)const{
        return ((p<v.p)||((p==v.p)&&sign(r-v.r)<0));
    }
    db area(){return PI*r*r;}
    db circumference(){return 2*PI*r;}
    //|0 not|1 on|2 in|
    int relation(Point b){
        db dst=b.distance(p);
        if(sign(dst-r)<0)return 2;
        else if(sign(dst-r)==0)return 1;
        return 0;
    }
    //|0 not|1 on|2 in|
    int relationseg(Line v){
        db dst=v.dispointtoseg(p);
        if(sign(dst-r)<0)return 2;
        else if(sign(dst-r)==0)return 1;
        return 0;
    }
    //|1 内含|2 内切|3 相交|4 外切|5 相离|
    int relationcircle(circle v){
        db d=p.distance(v.p);
        if(sign(d-r-v.r)>0)return 5;
        if(sign(d-r-v.r)==0)return 4;
        db l=fabs(r-v.r);
        if(sign(d-r-v.r)<0&&sign(d-l)>0)return 3;
        if(sign(d-l)==0)return 2;
        if(sign(d-l)<0)return 1;
    }
};
	//`求两个圆的交点，返回0表示没有交点，返回1是一个交点，2是两个交点`
	//`需要relationcircle`
	//`测试：UVA12304`
//	int pointcrosscircle(circle v,Point &p1,Point &p2){
//		int rel = relationcircle(v);
//		if(rel == 1 || rel == 5)return 0;
//		double d = p.distance(v.p);
//		double l = (d*d+r*r-v.r*v.r)/(2*d);
//		double h = sqrt(r*r-l*l);
//		Point tmp = p + (v.p-p).trunc(l);
//		p1 = tmp + ((v.p-p).rotleft().trunc(h));
//		p2 = tmp + ((v.p-p).rotright().trunc(h));
//		if(rel == 2 || rel == 4)
//			return 1;
//		return 2;
//	}
//	//`求直线和圆的交点，返回交点个数`
//	int pointcrossline(Line v,Point &p1,Point &p2){
//		if(!(*this).relationline(v))return 0;
//		Point a = v.lineprog(p);
//		double d = v.dispointtoline(p);
//		d = sqrt(r*r-d*d);
//		if(sgn(d) == 0){
//			p1 = a;
//			p2 = a;
//			return 1;
//		}
//		p1 = a + (v.e-v.s).trunc(d);
//		p2 = a - (v.e-v.s).trunc(d);
//		return 2;
//	}
//	//`得到过a,b两点，半径为r1的两个圆`
//	int gercircle(Point a,Point b,double r1,circle &c1,circle &c2){
//		circle x(a,r1),y(b,r1);
//		int t = x.pointcrosscircle(y,c1.p,c2.p);
//		if(!t)return 0;
//		c1.r = c2.r = r;
//		return t;
//	}
//	//`得到与直线u相切，过点q,半径为r1的圆`
//	//`测试：UVA12304`
//	int getcircle(Line u,Point q,double r1,circle &c1,circle &c2){
//		double dis = u.dispointtoline(q);
//		if(sgn(dis-r1*2)>0)return 0;
//		if(sgn(dis) == 0){
//			c1.p = q + ((u.e-u.s).rotleft().trunc(r1));
//			c2.p = q + ((u.e-u.s).rotright().trunc(r1));
//			c1.r = c2.r = r1;
//			return 2;
//		}
//		Line u1 = Line((u.s + (u.e-u.s).rotleft().trunc(r1)),(u.e + (u.e-u.s).rotleft().trunc(r1)));
//		Line u2 = Line((u.s + (u.e-u.s).rotright().trunc(r1)),(u.e + (u.e-u.s).rotright().trunc(r1)));
//		circle cc = circle(q,r1);
//		Point p1,p2;
//		if(!cc.pointcrossline(u1,p1,p2))cc.pointcrossline(u2,p1,p2);
//		c1 = circle(p1,r1);
//		if(p1 == p2){
//			c2 = c1;
//			return 1;
//		}
//		c2 = circle(p2,r1);
//		return 2;
//	}
//	//`同时与直线u,v相切，半径为r1的圆`
//	//`测试：UVA12304`
//	int getcircle(Line u,Line v,double r1,circle &c1,circle &c2,circle &c3,circle &c4){
//		if(u.parallel(v))return 0;//两直线平行
//		Line u1 = Line(u.s + (u.e-u.s).rotleft().trunc(r1),u.e + (u.e-u.s).rotleft().trunc(r1));
//		Line u2 = Line(u.s + (u.e-u.s).rotright().trunc(r1),u.e + (u.e-u.s).rotright().trunc(r1));
//		Line v1 = Line(v.s + (v.e-v.s).rotleft().trunc(r1),v.e + (v.e-v.s).rotleft().trunc(r1));
//		Line v2 = Line(v.s + (v.e-v.s).rotright().trunc(r1),v.e + (v.e-v.s).rotright().trunc(r1));
//		c1.r = c2.r = c3.r = c4.r = r1;
//		c1.p = u1.crosspoint(v1);
//		c2.p = u1.crosspoint(v2);
//		c3.p = u2.crosspoint(v1);
//		c4.p = u2.crosspoint(v2);
//		return 4;
//	}
//	//`同时与不相交圆cx,cy相切，半径为r1的圆`
//	//`测试：UVA12304`
//	int getcircle(circle cx,circle cy,double r1,circle &c1,circle &c2){
//		circle x(cx.p,r1+cx.r),y(cy.p,r1+cy.r);
//		int t = x.pointcrosscircle(y,c1.p,c2.p);
//		if(!t)return 0;
//		c1.r = c2.r = r1;
//		return t;
//	}
//
//	//`过一点作圆的切线(先判断点和圆的关系)`
//	//`测试：UVA12304`
//	int tangentline(Point q,Line &u,Line &v){
//		int x = relation(q);
//		if(x == 2)return 0;
//		if(x == 1){
//			u = Line(q,q + (q-p).rotleft());
//			v = u;
//			return 1;
//		}
//		double d = p.distance(q);
//		double l = r*r/d;
//		double h = sqrt(r*r-l*l);
//		u = Line(q,p + ((q-p).trunc(l) + (q-p).rotleft().trunc(h)));
//		v = Line(q,p + ((q-p).trunc(l) + (q-p).rotright().trunc(h)));
//		return 2;
//	}
//	//`求两圆相交的面积`
//	double areacircle(circle v){
//		int rel = relationcircle(v);
//		if(rel >= 4)return 0.0;
//		if(rel <= 2)return min(area(),v.area());
//		double d = p.distance(v.p);
//		double hf = (r+v.r+d)/2.0;
//		double ss = 2*sqrt(hf*(hf-r)*(hf-v.r)*(hf-d));
//		double a1 = acos((r*r+d*d-v.r*v.r)/(2.0*r*d));
//		a1 = a1*r*r;
//		double a2 = acos((v.r*v.r+d*d-r*r)/(2.0*v.r*d));
//		a2 = a2*v.r*v.r;
//		return a1+a2-ss;
//	}
//	//`求圆和三角形pab的相交面积`
//	//`测试：POJ3675 HDU3982 HDU2892`
//	double areatriangle(Point a,Point b){
//		if(sgn((p-a)^(p-b)) == 0)return 0.0;
//		Point q[5];
//		int len = 0;
//		q[len++] = a;
//		Line l(a,b);
//		Point p1,p2;
//		if(pointcrossline(l,q[1],q[2])==2){
//			if(sgn((a-q[1])*(b-q[1]))<0)q[len++] = q[1];
//			if(sgn((a-q[2])*(b-q[2]))<0)q[len++] = q[2];
//		}
//		q[len++] = b;
//		if(len == 4 && sgn((q[0]-q[1])*(q[2]-q[1]))>0)swap(q[1],q[2]);
//		double res = 0;
//		for(int i = 0;i < len-1;i++){
//			if(relation(q[i])==0||relation(q[i+1])==0){
//				double arg = p.rad(q[i],q[i+1]);
//				res += r*r*arg/2.0;
//			}
//			else{
//				res += fabs((q[i]-p)^(q[i+1]-p))/2.0;
//			}
//		}
//		return res;
//	}
//};
circle c1,c2;
int main()
{
    #ifdef io
    freopen("in.txt","r",stdin);
    #endif
    c1.input();c2.input();
    int t=c1.relationcircle(c2);
    if(t==5)puts("4");
    else if(t==4)puts("3");
    else if(t==3)puts("2");
    else if(t==2)puts("1");
    else puts("0");
    return 0;
}




Measured memory_bytes: 3268