#include <bits/stdc++.h>
using namespace std;
template <typename T>
inline void read(T& x) {
  int f = 0, c = getchar();
  x = 0;
  while (!isdigit(c)) f |= c == '-', c = getchar();
  while (isdigit(c)) x = x * 10 + c - 48, c = getchar();
  if (f) x = -x;
}
template <typename T, typename... Args>
inline void read(T& x, Args&... args) {
  read(x);
  read(args...);
}
template <typename T>
void write(T x) {
  if (x < 0) x = -x, putchar('-');
  if (x > 9) write(x / 10);
  putchar(x % 10 + 48);
}
template <typename T>
void writes(T x) {
  write(x);
  putchar(' ');
}
template <typename T>
void writeln(T x) {
  write(x);
  puts("");
}
template <typename T>
inline bool chkmin(T& x, const T& y) {
  return y < x ? (x = y, true) : false;
}
template <typename T>
inline bool chkmax(T& x, const T& y) {
  return x < y ? (x = y, true) : false;
}
const int maxn = (int)2e5 + 10;
const long long inf = (long long)1e18;
const long long mod = (long long)1e9 + 7;
long long N, M, K, L;
bool fail;
int main() {
  read(N, M, K, L);
  long long ans = 0;
  if (L + K > N || N < M)
    fail = 1;
  else {
    ans = (L + K) / M;
    if ((L + K) % M) ans++;
    if (ans * M > N) fail = 1;
  }
  if (fail)
    puts("-1");
  else
    write(ans);
}
