#include <bits/stdc++.h>
using namespace std;
const long long md = 1000 * 1000;
const int maxi = 102;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  long long n, m, k, l, resp;
  cin >> n >> m >> k >> l;
  if (m > n)
    resp = -1;
  else {
    resp = (l + k + m - 1) / m;
    if (resp * m > n) resp = -1;
  }
  cout << resp << endl;
}
