#include <bits/stdc++.h>
using namespace std;
const long long INF = 1e15;
const long double EPS = 1e-15;
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long n, m, k, l;
  cin >> n >> m >> k >> l;
  if (k + l > n) {
    cout << -1;
    return 0;
  }
  long long c;
  if ((l + k) % m == 0) {
    c = (l + k) / m;
  } else {
    c = (l + k) / m + 1;
  }
  if (n < c * m) {
    cout << -1;
    return 0;
  }
  cout << c;
}
