#include using namespace std; namespace { typedef double real; typedef long long ll; template ostream& operator<<(ostream& os, const vector& vs) { if (vs.empty()) return os << "[]"; os << "[" << vs[0]; for (int i = 1; i < vs.size(); i++) os << " " << vs[i]; return os << "]"; } template istream& operator>>(istream& is, vector& vs) { for (auto it = vs.begin(); it != vs.end(); it++) is >> *it; return is; } ll d; ll h[3]; void input() { cin >> d; for (int i = 0; i < 3; i++) cin >> h[i]; } const ll INF = 1LL<<50; ll calc() { ll p = 0; if (h[0] == h[2]) { p++; h[0] = max(0LL, h[0] - d); if (h[0] == h[2]) return INF; } if (h[0] > h[2]) swap(h[0], h[2]); ll lb = min(h[0], h[2]); ll ub = max(h[0], h[2]); if (h[1] > ub) return p; if (h[1] < lb) return p; assert(h[0] <= h[1] && h[1] <= h[2]); ll ans = INF; // 逵溘s荳ュ荳九£ ll x = ((h[1] - lb + 1) + d - 1) / d; if (lb != max(0LL, h[1] - d * x)) { ans = min(ans, x); } // 蜿ウ荳九£ ll y = ((h[2] - h[1] + 1) + d - 1) / d; if (h[1] != max(0LL, h[2] - d * y)) { if (h[0] != max(0LL, h[2] - d * y)) { ans = min(ans, y); } else { if (h[0] == max(0LL, h[2] - d * (y + 1))) { ans = -1; } else { ans = min(ans, y + 1); } } } return ans + p; } void solve() { ll a = calc(); cout << (a >= INF ? -1 : a) << endl; } } int main() { input(); solve(); return 0; }