#include <bits/stdc++.h>
#define ll long long
#define REP(i, n) for (ll i = 0, max_i = (n); i < max_i; i++)
#define REPI(i, a, b) for (ll i = (a), max_i = (b); i < max_i; i++)
#define ALL(obj) (obj).begin(), (obj).end()
#define RALL(obj) (obj).rbegin(), (obj).rend()
#define fi first
#define se second
#define pb push_back
#define debug(x) cerr << #x << ": " << (x) << endl
#define int long long
using namespace std;
using II = pair<int, int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VVVI = vector<VVI>;
template <class T = int> inline T in() { T x; cin >> x; return x; }
template <class T = int> inline bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }
template <class T = int> inline bool chmin(T &a, const T &b) { if (a > b) { a = b; return true; } return false; }
template <class T> ostream& operator<<(ostream &s, const vector<T>& d) { int n = d.size(); REP (i, n) s << d[i] << " "; return s; }
template <class T> ostream& operator<<(ostream &s, const vector<vector<T>>& dd) { for (vector<T> d: dd) s << d << endl; return s; }
struct Fast { Fast() { cin.tie(0); ios::sync_with_stdio(false); } } fast;
const int MOD = 1e9 + 7;

int d;
// h2をでかくする
int solve1(int h1, int h2, int h3) {
  int a1 = max(0ll, (h1 - h2 + d) / d);
  int a3 = max(0ll, (h3 - h2 + d) / d);
  h1 = max(0ll, h1 - d * a1);
  h3 = max(0ll, h3 - d * a3);
  if (h1 == h3 && h1 == 0) return 1e10;
  return a1 + a3 + (h1 == h3);
}
// h2を小さくする
int solve2(int h1, int h2, int h3) {
  int ans = 0;
  if (h1 == h3) {
    h1 = max(0ll, h1 - d);
    ans++;
  }
  if (h1 == 0 || h3 == 0) return 1e10;
  return ans + max(0ll, (h2 - min(h1, h3) + d) / d);
}

signed main() {
  int h1, h2, h3;
  cin >> d >> h1 >> h2 >> h3;
  if (d == 0) {
    if (((h2 > h1 && h2 > h3) || (h2 < h1 && h2 < h3)) && h1 != h2 && h2 != h3 && h3 != h1) {
      cout << 0 << endl; return 0;
    } else {
      cout << -1 << endl; return 0;
    }
  }
  int ans = min(solve1(h1, h2, h3), solve2(h1, h2, h3));
  cout << (ans == 1e10 ? -1 : ans) << endl;
}