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