#include <bits/stdc++.h>
inline long long read() {
  long long now = 0, f = 1;
  register char c = getchar();
  for (; !isdigit(c); c == '-' && (f = -1), c = getchar())
    ;
  for (; isdigit(c); now = now * 10 + c - '0', c = getchar())
    ;
  return now * f;
}
int main() {
  long long n = read(), m = read(), K = read(), L = read();
  long long ans = (L + K + m - 1) / m;
  if (ans * m > n)
    puts("-1");
  else
    printf("%I64d\n", ans);
  return 0;
}
