#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 22, INF = 0x3f3f3f3f;
long long n, m, k, l, ans;
int main() {
  ios::sync_with_stdio(false), cin.tie(0);
  cin >> n >> m >> k >> l;
  if (n - k < l) return cout << -1, 0;
  if ((l + k) % m)
    ans = (l + k) / m + 1;
  else
    ans = (l + k) / m;
  if (ans * m > n)
    cout << -1;
  else
    cout << ans;
  return 0;
}
