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