#include <bits/stdc++.h>
using namespace std;
int main() {
  long long N, M, K, L, aux;
  cin >> N >> M >> K >> L;
  aux = L + K;
  if (N < M) {
    cout << -1;
  } else if (N < L + K) {
    cout << -1;
  } else if (N == aux && aux % M != 0) {
    cout << -1;
  } else if (aux % M == 0) {
    cout << aux / M;
  } else if (aux % M != 0 && aux / M == N / M) {
    cout << -1;
  } else if (aux % M != 0 && aux / M != N / M) {
    cout << aux / M + 1;
  }
  return 0;
}
