package contest;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class Q661 {
	InputStream is;
	PrintWriter out;
	String INPUT = "";
	
	void solve()
	{
		int d = ni();
		int[] a = na(3);
		if(d == 0){
			if(
					a[0] > a[1] && a[1] < a[2] && a[0] != a[2] ||
					a[0] < a[1] && a[1] > a[2] && a[0] != a[2]){
				out.println(0);
			}else{
				out.println(-1);
			}
			return;
		}
		
		long min = Long.MAX_VALUE;
		{
			int[] b = Arrays.copyOf(a, 3);
			long num = 0;
			for(int i = 0;i < 3;i+=2){
				if(b[i] >= b[1]){
					num += (b[i]-b[1])/d+1;
					b[i] = b[i]-((b[i]-b[1])/d+1)*d;
					if(b[i] < 0)b[i] = 0;
				}
			}
			if(b[0] == b[2] && b[0] > 0){
				num++;
			}
			if(b[0] == b[1] || b[1] == b[2] || b[2] == b[0]){
			}else{
				min = Math.min(min, num);
			}
		}
		{
			int[] b = Arrays.copyOf(a, 3);
			long num = 0;
			if(b[0] == b[2]){
				b[0] = Math.max(0, b[0]-d);
				num++;
			}
			if(b[1]-Math.min(b[0],b[2]) >= 0){
				num += (b[1]-Math.min(b[0],b[2]))/d+1;
				b[1] = b[1] - ((b[1]-Math.min(b[0],b[2]))/d+1)*d;
				b[1] = Math.max(b[1], 0);
			}
			if(b[0] == b[1] || b[1] == b[2] || b[2] == b[0]){
			}else{
				min = Math.min(min, num);
			}
		}
		out.println(min == Long.MAX_VALUE ? -1 : min);
	}
	
	void run() throws Exception
	{
		is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
		out = new PrintWriter(System.out);
		
		long s = System.currentTimeMillis();
		solve();
		out.flush();
		if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
	}
	
	public static void main(String[] args) throws Exception { new Q661().run(); }
	
	private byte[] inbuf = new byte[1024];
	private int lenbuf = 0, ptrbuf = 0;
	
	private int readByte()
	{
		if(lenbuf == -1)throw new InputMismatchException();
		if(ptrbuf >= lenbuf){
			ptrbuf = 0;
			try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
			if(lenbuf <= 0)return -1;
		}
		return inbuf[ptrbuf++];
	}
	
	private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
	private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
	
	private double nd() { return Double.parseDouble(ns()); }
	private char nc() { return (char)skip(); }
	
	private String ns()
	{
		int b = skip();
		StringBuilder sb = new StringBuilder();
		while(!(isSpaceChar(b))){ // when nextLine, (isSpaceChar(b) && b != ' ')
			sb.appendCodePoint(b);
			b = readByte();
		}
		return sb.toString();
	}
	
	private char[] ns(int n)
	{
		char[] buf = new char[n];
		int b = skip(), p = 0;
		while(p < n && !(isSpaceChar(b))){
			buf[p++] = (char)b;
			b = readByte();
		}
		return n == p ? buf : Arrays.copyOf(buf, p);
	}
	
	private char[][] nm(int n, int m)
	{
		char[][] map = new char[n][];
		for(int i = 0;i < n;i++)map[i] = ns(m);
		return map;
	}
	
	private int[] na(int n)
	{
		int[] a = new int[n];
		for(int i = 0;i < n;i++)a[i] = ni();
		return a;
	}
	
	private int ni()
	{
		int num = 0, b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private long nl()
	{
		long num = 0;
		int b;
		boolean minus = false;
		while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
		if(b == '-'){
			minus = true;
			b = readByte();
		}
		
		while(true){
			if(b >= '0' && b <= '9'){
				num = num * 10 + (b - '0');
			}else{
				return minus ? -num : num;
			}
			b = readByte();
		}
	}
	
	private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }
}