#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, m, l, k;
  cin >> n >> m >> l >> k;
  long long ans = (k + l) / m;
  if ((k + l) % m != 0) ans++;
  if (ans * m > n)
    cout << "-1";
  else
    cout << ans;
  return 0;
}
