#include <bits/stdc++.h>
using namespace std;
class ABirthday {
 public:
  void solve(std::istream &in, std::ostream &out) {
    long long n, m, k, l;
    in >> n >> m >> k >> l;
    long long ans = k + l + m - 1;
    ans /= m;
    if (ans * m <= n and ans > 0)
      out << ans;
    else
      out << -1;
  }
};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ABirthday solver;
  std::istream &in(std::cin);
  std::ostream &out(std::cout);
  solver.solve(in, out);
  return 0;
}
