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