#include <bits/stdc++.h>
int main() {
  long long int n, m, k, l, a, b;
  scanf("%lld%lld%lld%lld", &n, &m, &k, &l);
  b = (l + k + m - 1) / m;
  if (b * m > n)
    printf("-1");
  else
    printf("%lld", b);
  return 0;
}
