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