#include <bits/stdc++.h>
#define EPS 1e-10
#define PI 3.141592653589793238
#define equals(a,b) (fabs((a)-(b)) < EPS)
#define rep(i,n) for(int i=0;i<n;++i)
typedef long long ll;
using namespace std;

static const int COUNTER_CLOCKWISE = 1;
static const int CLOCKWISE = -1;
static const int ONLINE_BACK = 2;
static const int ONLINE_FRONT = -2;
static const int ON_SEGMENT = 0;

//Intercsect Circle & Circle
static const int ICC_SEPERATE = 4;
static const int ICC_CIRCUMSCRIBE = 3;
static const int ICC_INTERSECT = 2;
static const int ICC_INSCRIBE = 1;
static const int ICC_CONTAIN = 0;

// 点
struct Point {
    double x,y;
    Point(){}
    Point(double x, double y) : x(x),y(y){}
    Point operator+(Point p) {return Point(x+p.x, y+p.y);}
    Point operator-(Point p) {return Point(x-p.x, y-p.y);}
    Point operator*(double k){return Point(x*k,y*k);}
    Point operator/(double k){return Point(x/k,y/k);}
    double norm(){return x*x+y*y;}
    double abs(){sqrt(norm());}
    bool operator == (const Point &p) const {return equals(x,p.x)&&equals(y,p.y);}
    bool operator < (const Point &p) const {
        return x!=p.x?x<p.x:y<p.y;
        //grid-point only
        //return !equals(x,p.x)?x<p.x:!equals(y,p.y)?y<p.y:0;
    }
};

typedef Point P;
typedef vector<Point> Polygon;

double norm(P a){return a.x*a.x+a.y*a.y;}
double abs(P a){return sqrt(norm(a));}

// 線分
struct Segment {
    Point p1,p2;
    Segment(){}
    Segment(Point p1, Point p2):p1(p1),p2(p2){}
};

typedef Segment Line;

struct Circle {
    Point c;
    double r;
    Circle(){}
    Circle(Point c, double r):c(c),r(r){}
};

// 法線ベクトル
Point normal(Point p){return Point(-p.y,p.x);}

// 内積
double dot(Point a, Point b) {return a.x*b.x + a.y*b.y;}

// 外積
double cross(Point a, Point b) {return a.x*b.y-a.y*b.x;}
// 2直線の直行判定
bool is_orthogonal(Point a1, Point a2, Point b1, Point b2) {
    return equals(dot(a1-a2, b1-b2), 0.0);
}
// 2直線の平行判定
bool is_parallel(Point a1, Point a2, Point b1, Point b2) {
    return equals(cross(a1-a2, b1-b2), 0.0);
}
// 点cが直線ab上にあるかないか
bool is_point_on_INF_line(Point a, Point b, Point c) {
    return equals(cross(b-a,c-a), 0.0);
}
// 点cが線分ab上にあるかないか
bool is_point_on_LIMITED_line(Point a, Point b, Point c) {
    return (Point(a-c).abs()+Point(c-b).abs() < Point(a-b).abs() + EPS);
}
// 直線と点の距離
double distance_l_p(Point a, Point b, Point c) {return abs(cross(b-a, c-a)) / (b-a).abs();}

// 点a,bを端点とする線分と点cとの距離
double distance_ls_p(Point a, Point b, Point c) {
    if (dot(b-a, c-a) < EPS) return (c-a).abs();
    if (dot(a-b, c-b) < EPS) return (c-b).abs();
    return abs(cross(b-a, c-a)) / (b-a).abs();
}

// 点が線分のどちら側にあるかを計算
int ccw(Point p0,Point p1,Point p2) {
    P a = p1-p0;
    P b = p2-p0;
    if(cross(a,b) > EPS) return COUNTER_CLOCKWISE;
    if(cross(a,b) < -EPS) return CLOCKWISE;
    if(dot(a,b) < -EPS) return ONLINE_BACK;
    if(a.norm()<b.norm()) return ONLINE_FRONT;
    return ON_SEGMENT;
}

// a1,a2を端点とする線分とb1,b2を端点とする線分の交差判定
bool intersectSS(Point p1, Point p2, Point p3, Point p4) {
    return (ccw(p1,p2,p3)*ccw(p1,p2,p4) <= 0&&ccw(p3,p4,p1)*ccw(p3,p4,p2) <= 0 );
}

// a1,a2を端点とする線分とb1,b2を端点とする線分の交差判定
bool intersectSS(Segment s1, Segment s2) {
    return intersectSS(s1.p1,s1.p2,s2.p1,s2.p2);
}

// 多角形と線分の交差判定
bool intersectPS(Polygon p,Segment l) {
    int n=p.size();
    for(int i=0;i<n;i++)
    if(intersectSS(Segment(p[i],p[(i+1)%n]),l)) return 1;
    return 0;
}

// 円と円の交差判定(共通接線の数)
int intersectCC(Circle c1,Circle c2) {
    if(c1.r<c2.r) swap(c1,c2);
    double d=abs(c1.c-c2.c);
    double r=c1.r+c2.r;
    if(equals(d,r)) return ICC_CIRCUMSCRIBE;
    if(d>r) return ICC_SEPERATE;
    if(equals(d+c2.r,c1.r)) return ICC_INSCRIBE;
    if(d+c2.r<c1.r) return ICC_CONTAIN;
    return ICC_INTERSECT;
}

int main() {
    double x0,y0,r0,x1,y1,r1;
    cin>>x0>>y0>>r0>>x1>>y1>>r1;
    Circle c0(Point(x0,y0),r0),c1(Point(x1,y1),r1);
    cout<<intersectCC(c0,c1)<<endl;
}
