#include <bits/stdc++.h>
using namespace std;
const long long M = 1e9 + 7;
const long long MM = 998244353;
void solve() {
  long long n, m, k, l;
  cin >> n >> m >> k >> l;
  long long ans = (l + k) / m + ((k + l) % m > 0);
  if (ans * m > n)
    cout << -1 << "\n";
  else
    cout << ans << "\n";
  return;
}
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long t = 1;
  while (t--) solve();
  return 0;
}
