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