#define _USE_MATH_DEFINES
#include <algorithm>
#include <cstdio>
#include <functional>
#include <iostream>
#include <cfloat>
#include <climits>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <time.h>
#include <vector>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<ll, int> ll_i;
typedef pair<double, int> d_i;
typedef pair<ll, ll> ll_ll;
typedef pair<double, double> d_d;
struct edge { int u, v; ll w; };

ll MOD = 1000000007;
ll _MOD = 1000000009;
double EPS = 1e-10;

int main() {
	ll d; cin >> d;
	if (d == 0) {
		cout << -1 << endl;
		return 0;
	}
	ll a, b, c; cin >> a >> b >> c;
	ll x = (max(0LL, b - min(a, c) + 1) + d - 1) / d;
	if (a == 0 || c == 0) x = INT_MAX;
	ll y = (max(0LL, a - b + 1) + d - 1) / d + (max(0LL, c - b + 1) + d - 1) / d;
	if (b == 0) y = INT_MAX;
	ll z = min(x, y);
	if (z == INT_MAX) z = -1;
	cout << z << endl;
}