#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:16777216")
using namespace std;
const unsigned long long MOD = 1e9 + 7;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cout.precision(20);
  unsigned long long n, l, k, m;
  cin >> n >> m >> k >> l;
  unsigned long long ans = (l + k) / m;
  if ((l + k) % m != 0) ans++;
  if (ans * m > n) {
    cout << -1;
  } else
    cout << ans;
  return 0;
}
