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

namespace Solver
{
    class Program
    {
        const int M = 1000000007;
        const double eps = 1e-9;
        static int d;
        static void Main()
        {
            var sw = new System.IO.StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            var sc = new Scan();
            d = sc.Int;
            var h = new int[3];
            for (int i = 0; i < 3; i++)
                h[i] = sc.Int;

            long bi = 10000000000000;
            long ans = bi;
            ans = Math.Min(ans, count(h[1], h[0], h[2]));
            ans = Math.Min(ans, count(h[1], h[2], h[0]));
            ans = Math.Min(ans, count(h[0], h[2], h[1]));
            ans = Math.Min(ans, count(h[2], h[0], h[1]));
            if (ans == bi)
                sw.WriteLine("-1");
            else
                sw.WriteLine(ans);

            sw.Flush();
        }
        static long count(int sml, int mid, int big)
        {
            long bi = 10000000000000;
            if (d == 0)
            {
                if (sml < mid && mid < big)
                    return 0;

                return bi;
            }
            long ret = 0;
            long s = sml, m = mid, b = big;
            if (b <= m)
            {
                long t = (m - b) / d + 1;
                m -= t * d;
                if (m <= 0)
                    return bi;

                ret += t;
            }
            if (m <= s)
            {
                long t = (s - m) / d + 1;
                ret += t;
            }
            return ret;
        }

        static long pow(long a, long b)
        {
            if (b == 0)
                return 1;
            if (b == 1)
                return a % M;

            long t = pow(a, b / 2);
            if ((b & 1) == 0)
                return t * t % M;
            else
                return t * t % M * a % M;
        }
    }
    class Scan
    {
        public int Int { get { return int.Parse(Console.ReadLine().Trim()); } }
        public long Long { get { return long.Parse(Console.ReadLine().Trim()); } }
        public string Str { get { return Console.ReadLine().Trim(); } }
        public int[] IntArr { get { return Console.ReadLine().Trim().Split().Select(int.Parse).ToArray(); } }
        public int[] IntArrWithSep(char sep) { return Console.ReadLine().Trim().Split(sep).Select(int.Parse).ToArray(); }
        public long[] LongArr { get { return Console.ReadLine().Trim().Split().Select(long.Parse).ToArray(); } }
        public double[] DoubleArr { get { return Console.ReadLine().Split().Select(double.Parse).ToArray(); } }
        public string[] StrArr { get { return Console.ReadLine().Trim().Split(); } }
        public List<int> IntList { get { return Console.ReadLine().Trim().Split().Select(int.Parse).ToList(); } }
        public List<long> LongList { get { return Console.ReadLine().Trim().Split().Select(long.Parse).ToList(); } }
        public void Multi(out int a, out int b) { var arr = IntArr; a = arr[0]; b = arr[1]; }
        public void Multi(out int a, out int b, out int c) { var arr = IntArr; a = arr[0]; b = arr[1]; c = arr[2]; }
        public void Multi(out int a, out int b, out int c, out int d) { var arr = IntArr; a = arr[0]; b = arr[1]; c = arr[2]; d = arr[3]; }
        public void Multi(out int a, out string b) { var arr = StrArr; a = int.Parse(arr[0]); b = arr[1]; }
        public void Multi(out int a, out int b, out string c) { var arr = StrArr; a = int.Parse(arr[0]); b = int.Parse(arr[1]); c = arr[2]; }
        public void Multi(out int a, out char b) { var arr = StrArr; a = int.Parse(arr[0]); b = arr[1][0]; }
        public void Multi(out long a, out long b) { var arr = LongArr; a = arr[0]; b = arr[1]; }
        public void Multi(out long a, out int b) { var arr = LongArr; a = arr[0]; b = (int)arr[1]; }
        public void Multi(out string a, out string b) { var arr = StrArr; a = arr[0]; b = arr[1]; }
    }
}