#include <bits/stdc++.h>
#define rep(i, a) rep2 (i, 0, a)
#define rep2(i, a, b) for (int i = (a); i < (b); i++)
#define repr(i, a) repr2 (i, 0, a)
#define repr2(i, a, b) for (int i = (b) - 1; i >= (a); i--)
#define chmin(a, b) ((b) < a && (a = (b), true))
#define chmax(a, b) (a < (b) && (a = (b), true))
#define rng(a) (a).begin(), (a).end()
using namespace std;
typedef long long ll;

int main() {
    ll d, h1, h2, h3;
    cin >> d >> h1 >> h2 >> h3;
    if (h1 < h2 && h2 > h3 && h1 != h3) {
        cout << 0 << endl;		
        return 0;
    }
    if (h1 > h2 && h2 < h3 && h1 != h3) {
        cout << 0 << endl;
        return 0;
    }
    if (d == 0) {
    	cout << -1 << endl;
    	return 0;
    }
    const ll inf = 1e18;
    auto f = [&](ll a, ll b) { 
        if (a < b) return inf;
        return (a - b + d) / d; 
    };
    auto g = [&](ll a) {
        return max(0ll, a - d);
    };
    ll ans = inf;
    {
        ll th1 = h1;
        ll cand = 0;
        if (th1 == h3) th1 = g(th1), cand++;
        ll c = f(h2, min(th1, h3));	
        cand += c;
        ll th2 = max(0ll, h2 - c * d);
        if (th1 == th2 || th2 == h3 || h3 == th1) cand = inf;
        cerr << cand << endl;
        chmin(ans, cand);
    }
    {
        ll th3 = h3;
        ll cand = 0;
        if (h2 == th3) th3 = g(th3), cand++;
        ll c = f(h1, h3);
        cand += c;
        ll th1 = max(0ll, h1 - c * d);
        if (th1 == h2 || h2 == th3 || th3 == th1) cand = inf;
        cerr << cand << endl;
        chmin(ans, cand);
    }
    {
        ll th1 = h1;
        ll cand = 0;
        if (th1 == h2) th1 = g(th1), cand++;
        ll c = f(h3, h2);
        cand += c;
        ll th3 = max(0ll, h3 - c * d);
        if (th1 == h2 || h2 == th3 || th3 == th1) cand = inf;
        cerr << cand << endl;
        chmin(ans, cand);
    }
    if (ans >= inf) ans = -1;
    cout << ans << endl;
}