#include <bits/stdc++.h>
using namespace std;
const int mod = 1e9 + 7;
vector<long long> p;
int ho, mi, se;
void fix_time() {
  if (se > 59) mi += se / 60, se = se % 60;
  if (se < 0) se += 60, mi--;
  if (mi > 59) ho += mi / 60, mi = mi % 60;
  if (mi < 0) mi += 60, ho--;
  if (ho < 0) ho += 24;
  if (ho > 24) ho -= 24;
}
long long my_pow(int x, int y) {
  long long num = 1;
  for (long long i = x; y > 0; i = (i * i), y >>= 1)
    if (y & 1) num = (num * i);
  return num;
}
bool prime[16000003];
void sieve() {
  for (int i = 2; i <= 16000000; i += 2) prime[i] = false, prime[i - 1] = true;
  prime[2] = true;
  for (int i = 3; i <= 4000; i += 2)
    if (prime[i])
      for (int j = i * i; j <= 16000000; j += 2 * i) prime[j] = false;
}
void pfact(long long x) {
  if (x % 2 == 0) {
    p.push_back(2);
    while (x % 2 == 0) x /= 2;
  }
  for (long long i = 3; i * i <= x; i += 2)
    if (x % i == 0) {
      p.push_back(i);
      while (x % i == 0) x /= i;
    }
  if (x > 1) p.push_back(x);
}
int gcd(int a, int b) {
  if (b == 0) return a;
  a %= b;
  return gcd(b, a);
}
long long m, x, n, y, z, k, mx, one, gd, x2, y2, two,
    mn = 1e9, mid, l, r, pos, t, a[500003], b[500003], c[500000];
string s, s2;
vector<int> v, v2;
long long ans, num1, num, num2, num3;
char ch;
vector<pair<int, char>> r1, r2;
map<char, int> mp;
int main() {
  ios_base::sync_with_stdio(false);
  cin >> n >> m >> k >> l;
  long long tmp = (l + k + m - 1) / m;
  if (tmp * m > n)
    cout << -1;
  else
    cout << tmp;
  return 0;
}
