#include<iostream>
#include<cstdio>
#include<cstring>
#include<string>
#include<cctype>
#include<cstdlib>
#include<algorithm>
#include<bitset>
#include<vector>
#include<list>
#include<deque>
#include<queue>
#include<map>
#include<set>
#include<stack>
#include<cmath>
#include<sstream>
#include<fstream>
#include<iomanip>
#include<ctime>
#include<complex>
#include<functional>
#include<climits>
#include<cassert>
#include<iterator>
#include<unordered_map>
#include<unordered_set>
//#include<quadmath.h>
using namespace std;
long long int a[3];
long long int tmp[3];
long long int d;
int calculate_distance(int a, int b){
	if (a > b){
		swap(a, b);
	}
	swap(a, b);
	int dd = a - b;
	dd /= d;
	dd++;
	return dd;
}
long long int solve_min(){
	if (a[0] == 0 || a[2] == 0){
		return -1LL;
	}
	if (a[0] == a[1] || a[1] == a[2]){
		return -1LL;
	}
	bool update = true;
	while (update){
		update = false;
		if (a[0] < a[1]){
			int k = a[1] - a[0];
			if (k <= d || k%d == 0){
				return -1LL;
			}
		}
		if (a[2] < a[1]){
			int k = a[1] - a[2];
			if (k <= d || k%d == 0){
				return -1LL;
			}
		}
		return calculate_distance(min(a[0], a[2]), a[1]);
		if (a[0] < a[1] && a[2] < a[1]){
			int countt = 0;
			int ta;
			int tb;
			if (a[0] > a[2]){
				int tep = a[0]-a[2];
				tep /= d;
				if (tep*d < a[0] - a[2]){
					tep++;
				}
				ta = max(static_cast<int>(a[0]-tep*d),0);
				tb = a[2];
				countt += tep;
			}
			else{
				int tep = a[2] - a[0];
				tep /= d;
				if (tep*d < a[2] - a[0]){
					tep++;
				}
				tb = max(static_cast<int>(a[2]-tep*d),0);
				ta = a[0];
				countt += tep;
			}
			if (ta == tb){
				countt += calculate_distance(ta, a[1]);
			}
			else{
				countt += calculate_distance(ta, a[1]);
				countt += calculate_distance(tb, a[1]);
			}
			return countt;
		}
		else{
			if (a[0] < a[1]){
				return calculate_distance(a[0], a[1]);
			}
			else{
				if (a[2] < a[1]){
					return calculate_distance(a[2], a[1]);
				}
				else{
					return 0LL;
				}
			}
		}
	}
}
long long int solve_max(){
	if (a[0] == a[1] || a[1] == a[2]){
		return -1LL;
	}
	if (a[0] > a[1]){
		if ((a[0] - a[1]) % d == 0){
			return -1LL;
		}
	}
	if (a[2] > a[1]){
		if ((a[2] - a[1]) % d == 0){
			return -1LL;
		}
	}
	if (a[0] < a[2]){
		swap(a[0], a[2]);
	}
	if (a[0] > a[1] && a[2] > a[1]){
		int countt = 0;
		int ta;
		int tb;
		int dist = a[0] - a[2];
		if (dist%d){
			return calculate_distance(max(a[0],a[2]),a[1]);
		}
		else{
			return calculate_distance(a[0], a[1]) + calculate_distance(a[0], a[2]);
		}
	}
	else{
		if (a[0] > a[1]){
			return calculate_distance(a[0], a[1]);
		}
		else{
			if (a[2] > a[1]){
				return calculate_distance(a[1], a[2]);
			}
			else{
				return 0LL;
			}
		}
	}
}
long long int solvemin(){
	long long int k = min(a[0], a[2]);
	if (k > a[1]){
		return 0;
	}
	else{
		if (k == 0){
			return -1;
		}
		return calculate_distance(a[1], k);
	}
}
long long int solvemax(){
	long long int countt = 0;
	if (a[1] == 0){
		return -1LL;
	}
	if (a[0] >= a[1]){
		countt += calculate_distance(a[0], a[1]);
	}
	if (a[2] >= a[1]){
		countt += calculate_distance(a[1], a[2]);
	}
	return countt;
}
int main(){
	scanf("%lld", &d);
	for (int i = 0; i < 3; i++){
		scanf("%lld", &a[i]);
	}
	long long int ans = solvemin();
	if (ans != -1LL){
		ans = min(ans, solvemax());
	}
	else{
		ans = solvemax();
	}
	printf("%lld\n", ans);
	return 0;
}