#include <bits/stdc++.h>
using namespace std;
inline long long read() {
  long long x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    char ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = (x << 1) + (x << 3) + (ch ^ 48);
    ch = getchar();
  }
  return x * f;
}
long long n, m, k, l;
long long t, ans;
int main() {
  n = read();
  m = read();
  k = read();
  l = read();
  t = k + l;
  ans = t / m + (t % m ? 1 : 0);
  if (ans * m > n)
    printf("-1");
  else
    cout << ans;
  return 0;
}
