#include using namespace std; using ll = long long; using ld = long double; using VI = vector; using VL = vector; using VS = vector; template using PQ = priority_queue, greater>; #define FOR(i,a,n) for(int i=(a);i<(n);++i) #define eFOR(i,a,n) for(int i=(a);i<=(n);++i) #define rFOR(i,a,n) for(int i=(n)-1;i>=(a);--i) #define erFOR(i,a,n) for(int i=(n);i>=(a);--i) #define SORT(a) sort(a.begin(),a.end()) #define rSORT(a) sort(a.rbegin(),a.rend()) #define fSORT(a,f) sort(a.begin(),a.end(),f) #define all(a) a.begin(),a.end() #define out(y,x) ((y)<0||h<=(y)||(x)<0||w<=(x)) #define tp(a,i) get(a) #ifdef _DEBUG #define line cout << "-----------------------------\n" #define stop system("pause") #define debug(x) print(x) #endif constexpr ll INF = 1000000000; constexpr ll LLINF = 1LL << 60; constexpr ll mod = 1000000007; constexpr ll MOD = 998244353; constexpr ld eps = 1e-10; constexpr ld pi = 3.1415926535897932; templateinline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; }return false; } templateinline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; }return false; } inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } templateinline istream& operator>>(istream& is, vector& v) { for (auto& a : v)is >> a; return is; } templateinline istream& operator>>(istream& is, pair& p) { is >> p.first >> p.second; return is; } templateinline vector vec(size_t a) { return vector(a); } templateinline vector defvec(T def, size_t a) { return vector(a, def); } templateinline auto vec(size_t a, Ts... ts) { return vector(ts...))>(a, vec(ts...)); } templateinline auto defvec(T def, size_t a, Ts... ts) { return vector(def, ts...))>(a, defvec(def, ts...)); } templateinline void print(const T& a) { cout << a << "\n"; } templateinline void print(const T& a, const Ts&... ts) { cout << a << " "; print(ts...); } templateinline void print(const vector& v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); } templateinline void print(const vector>& v) { for (auto& a : v)print(a); } inline string reversed(const string& s) { string t = s; reverse(all(t)); return t; } templateinline T sum(const vector& a, int l, int r) { return a[r] - (l == 0 ? 0 : a[l - 1]); } templateinline void END(T s) { print(s); exit(0); } void END() { exit(0); } ll d; ll solve_max(VL h) { if (h[1] == 0)return LLINF; ll ans = 0; if (h[0] >= h[1]) { ll k = (h[0] - h[1] + d) / d; h[0] = max(0LL, h[0] - d * k); ans += k; } if (h[1] <= h[2]) { ll k = (h[2] - h[1] + d) / d; h[2] = max(0LL, h[2] - d * k); ans += k; } if (h[0] == h[2]) { if (h[0] == 0)return LLINF; else return ans + 1; } else return ans; } ll solve_min(VL h) { ll ans = 0; if (h[0] == h[2]) { h[0] = max(h[0] - d, 0LL); ++ans; } if (h[0] > h[2])swap(h[0], h[2]); if (h[0] == 0)return LLINF; if (h[0] <= h[1]) { ll k = (h[1] - h[0] + d) / d; h[1] = max(0LL, h[1] - d * k); ans += k; } return ans; } int main() { init(); cin >> d; VL h(3); cin >> h; if (d == 0) { if (h[0] != h[2] && ((h[0] h[2]) || (h[0] > h[1] && h[1] < h[2]))) END(0); else END(-1); } ll ans = min(solve_max(h), solve_min(h)); print(ans == LLINF ? -1 : ans); return 0; }