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