#include <bits/stdc++.h>
using namespace std;
const double pi = 3.141592653;
const long long MOD = 1000000007;
const long long mod = 998244353;
const string no = "NO\n", yes = "YES\n";
using namespace std;
int main() {
  long long n, m, k, length, i, j;
  cin >> n >> m >> k >> length;
  long long mi;
  mi = (length + k + m - 1) / m;
  if (mi * m > n)
    cout << -1;
  else
    cout << mi;
  return 0;
}
