#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  long long n, m, k, l;
  scanf("%lld%lld%lld%lld", &n, &m, &k, &l);
  n /= m;
  m = (m + k + l - 1) / m;
  printf("%lld\n", (n >= m) ? m : -1);
  return 0;
}
