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