#include <bits/stdc++.h>
using namespace std;
const int N = 200005;
int a[N];
int main() {
  int n, k;
  scanf("%i %i", &n, &k);
  for (int i = 1; i <= n; i++) scanf("%i", &a[i]);
  long long sum_pre = 0;
  int removed = 0;
  for (int i = 1; i <= n; i++) {
    int ii = i - removed;
    long long rating = sum_pre - (long long)(ii - 1) *
                                     (long long)(n - ii - removed) *
                                     (long long)a[i];
    if (rating < k) {
      printf("%i\n", i);
      removed++;
    } else
      sum_pre += a[i] * (ii - 1);
  }
  return 0;
}
