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