#include <bits/stdc++.h>
using namespace std;
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  long long n, m, k, l;
  cin >> n >> m >> k >> l;
  if (n - k < l) {
    cout << -1;
    return 0;
  } else {
    long long cnt;
    if ((l + k) % m == 0) {
      cnt = (l + k) / m;
    } else
      cnt = ((l + k) / m) + 1;
    if (cnt * m > n)
      cout << -1;
    else
      cout << cnt;
  }
  cerr << "\nTime: " << (double)clock() / CLOCKS_PER_SEC << endl;
  return 0;
}
