#include <algorithm>
#include <cfloat>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <memory>
#include <queue>
#include <deque>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>
#include <cassert>
#include <iostream>
#include <stdio.h>
#include <time.h>
 
using namespace std;
 
#define sz size()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(c) (c).begin(), (c).end()
#define rep(i,a,b) for(int i=(a);i<(b);++i)
#define clr(a, b) memset((a), (b) ,sizeof(a))
 
#define MOD 1000000007

int check(int a, int b, int c){
  if(a==b||a==c||b==c)return 0;
  vector<int> v;
  v.pb(a);v.pb(b);v.pb(c);
  sort(all(v));
  if(b==v[1])return 0;
  return 1;
}

int main(){
  int d;
  cin>>d;
  int h1,h2,h3;
  cin>>h1>>h2>>h3;
  int ans = 2000000000;
  if(check(h1,h2,h3)){
    cout << ans << endl;
    return 0;
  }
  else if(d==0){
    cout << -1 << endl;
    return 0;
  }
  rep(i,0,3){
    rep(j,0,3){
      rep(k,0,3){
        int a = max(0,h1-d*i);
        int b = max(0,h2-d*j);
        int c = max(0,h3-d*k);
        if(check(a,b,c)){
          ans = min(ans,i+j+k);
        }
      }
    }
  }
  int mn = min(h1,h3);
  if(mn==0||((h1<2)&&(h3<2))){
    cout << -1 << endl;
  }
  cout << min(ans, (h2-mn)/d+1) << endl;
  return 0;
}