package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	solve281()
}

func solve281() {
	//var d, a, b, c int
	d := nextInt()
	a := nextInt()
	b := nextInt()
	c := nextInt()
	if isKadomatsu(a, b, c) {
		fmt.Println("0")
		return
	} else if d == 0 {
		// d == 0 のとき, なにも操作できない
		fmt.Println("-1")
		return
	}

	var cnt1, cnt2 int

	// 真ん中を下げる用意
	b1 := b
	// 左右のどちらかが0だと不成立
	if a == 0 || c == 0 {
		cnt1 = -1
	} else {
		// 左右a,cが同値のときは先に一方(a)を下げておく
		aa := a
		if a == c {
			cnt1++
			aa = a - d
		}

		foo := ((b - min(aa, c)) / d) + 1
		if foo > 0 {
			cnt1 += foo
			b1 = max(0, b1-d*foo)
		}

		if isKadomatsu(aa, b1, c) == false {
			cnt1 = -1
		}
	}

	// 左右を下げる
	if b == 0 {
		cnt2 = -1
	} else {
		a1 := a
		if a > 0 {
			bar := ((a - b) / d) + 1
			if bar > 0 {
				cnt2 = bar
				a1 = max(0, a1-d*bar)
			}
		}
		c1 := c
		if c > 0 {
			foobar := ((c - b) / d) + 1
			if foobar > 0 {
				cnt2 += foobar
				c1 = max(0, c1-d*foobar)
			}
		}
		ax := a
		if a == c && cnt2 >= 0 {
			ax = max(0, ax-d)
			cnt2++
		}
		if isKadomatsu(ax, b, c1) == false {
			cnt2 = -1
		}
	}

	if cnt1 == -1 && cnt2 == -1 {
		fmt.Println("-1")
	} else if cnt1 == -1 {
		fmt.Println(cnt2)
	} else if cnt2 == -1 {
		fmt.Println(cnt1)
	} else {
		fmt.Println(min(cnt1, cnt2))
	}
	//fmt.Println(cnt1, cnt2)
	//fmt.Println(a,b1,c)
	return
}

// 門松判定器
func isKadomatsu(a, b, c int) bool {
	if a < b && b > c && a != c {
		return true
	} else if a > b && b < c && a != c {
		return true
	}
	return false
}

func max(a, b int) int {
	if a < b {
		a = b
	}
	return a
}

func min(a, b int) int {
	if a > b {
		a = b
	}
	return a
}

var s = bufio.NewScanner(os.Stdin)

func next() string {
	s.Split(bufio.ScanWords)
	s.Scan()
	return s.Text()
}

func nextInt() int {
	i, e := strconv.Atoi(next())
	if e != nil {
		panic(e)
	}
	return i
}