#include <bits/stdc++.h>
using namespace std;
signed main(void) {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long N, M, K, L;
  cin >> N >> M >> K >> L;
  long long coin = (L + K - 1 + M) / M;
  if (M * coin > N) {
    cout << -1 << endl;
    return 0;
  }
  cout << (L + K - 1 + M) / M << endl;
  return 0;
}
