using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1
{
    enum ST { Bottom, Left, Right, Top }

    class Program
    {
        static void Main(string[] args)
        {
            Circle[] C = new Circle[2];
            for (int i = 0; i < 2; i++)
            {
                double[] input = Array.ConvertAll(Console.ReadLine().Split(' '), double.Parse);
                C[i] = new Circle(new Point(input[0], input[1]), input[2]);
            }
            Console.WriteLine(Intersect(C[0], C[1]));
        }

        static int Intersect(Circle c1, Circle c2)
        {
            double distP, distR;
            distP = (c1.p - c2.p).Norm;

            distR = (c1.r + c2.r) * (c1.r + c2.r);
            if (distP > distR) return 4;
            if (distP == distR) return 3;

            distR = (c1.r - c2.r) * (c1.r - c2.r);
            if (distP > distR) return 2;
            if (distP == distR) return 1;

            return 0;
        }
    }

    class EndPoint : IComparable
    {
        internal Point p;
        internal int seg;
        internal ST st;

        public EndPoint(Point p, int seg, ST st)
        {
            this.p = p;
            this.seg = seg;
            this.st = st;
        }

        public int CompareTo(object obj)
        {
            EndPoint other = obj as EndPoint;

            if (p.y < other.p.y) return -1;
            if (p.y > other.p.y) return 1;
            if (st < other.st) return -1;
            if (st > other.st) return 1;
            return 0;
        }
    }

    class Point : IComparable
    {
        static readonly double EPS = 1E-10;

        internal double x, y;

        public Point(double x, double y)
        {
            this.x = x;
            this.y = y;
        }

        public double Abs { get { return Math.Sqrt(Norm); } }
        public double Norm { get { return x * x + y * y; } }

        public double Dot(Point p) { return x * p.x + y * p.y; }
        public double Cross(Point p) { return x * p.y - y * p.x; }
        public double Distance(Point p) { return (this - p).Abs; }

        public static Point operator +(Point a, Point b) { return new Point(a.x + b.x, a.y + b.y); }
        public static Point operator -(Point a, Point b) { return new Point(a.x - b.x, a.y - b.y); }
        public static Point operator *(Point p, double d) { return new Point(p.x * d, p.y * d); }
        public static Point operator /(Point p, double d) { return new Point(p.x / d, p.y / d); }
        public static bool operator <(Point a, Point b) { return Math.Abs(a.x - b.x) > EPS ? a.x < b.x : a.y < b.y; }
        public static bool operator >(Point a, Point b) { return Math.Abs(a.x - b.x) > EPS ? a.x > b.x : a.y > b.y; }
        public static bool operator ==(Point a, Point b) { return Math.Abs(a.x - b.x) < EPS && Math.Abs(a.y - b.y) < EPS; }
        public static bool operator !=(Point a, Point b) { return Math.Abs(a.x - b.x) >= EPS || Math.Abs(a.y - b.y) >= EPS; }

        public int CompareTo(object obj)
        {
            var other = obj as Point;
            if (other == null) return -1;

            ComparerX compX = new ComparerX();
            return compX.Compare(this, other);
        }

        public override bool Equals(object obj)
        {
            var other = obj as Point;
            return Math.Abs(x - other.x) < EPS && Math.Abs(y - other.y) < EPS;
        }

        public override int GetHashCode()
        {
            return x.GetHashCode() ^ y.GetHashCode();
        }

        public override string ToString()
        {
            return string.Format("{0} {1}", x, y);
        }
    }

    class ComparerX : IComparer<Point>
    {
        static readonly double EPS = 1E-10;

        public int Compare(Point a, Point b)
        {
            if (a.x - b.x < -EPS) return -1;
            if (a.x - b.x > EPS) return 1;
            if (a.y - b.y < -EPS) return -1;
            if (a.y - b.y > EPS) return 1;
            return 0;
        }
    }

    class ComparerY : IComparer<Point>
    {
        static readonly double EPS = 1E-10;

        public int Compare(Point a, Point b)
        {
            if (a.y - b.y < -EPS) return -1;
            if (a.y - b.y > EPS) return 1;
            if (a.x - b.x < -EPS) return -1;
            if (a.x - b.x > EPS) return 1;
            return 0;
        }
    }

    class Segment
    {
        internal Point p1, p2;

        public Segment(Point p1, Point p2)
        {
            this.p1 = p1;
            this.p2 = p2;
        }
    }

    class Circle
    {
        internal Point p;
        internal double r;

        public Circle(Point p, double r)
        {
            this.p = p;
            this.r = r;
        }
    }
}

Measured memory_bytes: 9296