#include <bits/stdc++.h>
using namespace std;
int main() {
  unsigned long long N, M, L, K, X;
  cin >> N >> M >> K >> L;
  if (K + L > N) {
    cout << -1 << endl;
    return 0;
  }
  X = (K + L) / M;
  if (X * M < K + L) {
    X++;
  }
  if (X * M > N) {
    cout << -1;
    return 0;
  }
  cout << X << endl;
}
