#include <bits/stdc++.h>
const long long MOD = 1000000007ll;
using namespace std;
void pause(long long id) {
  long long temp;
  cout << "OK waiting with " << id << endl;
  cin >> temp;
  return;
}
int main() {
  long long n, m, k, l;
  cin >> n >> m >> k >> l;
  long long x = (l + k) / m;
  if (((l + k) % m) != 0) {
    x++;
  }
  if (x * m > n) {
    cout << -1 << endl;
    return 0;
  }
  cout << x << endl;
  return 0;
}
