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