#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, m, k, l, f = 0;
  cin >> n >> m >> k >> l;
  long long int req = l + k;
  long long int num = m;
  long long int i = 0;
  if (req % m == 0)
    i = req / m;
  else
    i = req / m + 1;
  num = m * i;
  if (num <= (n) && num >= req) {
    if (i == 0) {
      cout << 1 << endl;
    } else
      cout << i;
  } else
    cout << "-1";
}
