#include <bits/stdc++.h>
using namespace std;
inline void display(vector<long long int> v) {
  for (auto x : v) cout << x << " ";
  cout << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long int n, m, k, l;
  cin >> n >> m >> k >> l;
  long long int ans = (l + k) / m;
  if (ans * m < (l + k)) ans++;
  if (ans * m <= n)
    cout << ans;
  else
    cout << "-1";
  return 0;
}
