#include <bits/stdc++.h>
int const maxn = 210000;
long long a[maxn];
int n, k;
int main() {
  std::scanf("%d %d", &n, &k);
  for (int i = 1; i <= n; i++) std::scanf("%I64d", &a[i]);
  long long sum = 0, now = 2, tot = n;
  for (int i = 2; i <= n; i++) {
    long long tmp = sum - (now - 1) * (tot - now) * a[i];
    if (tmp < k) {
      std::printf("%d\n", i);
      tot--;
    } else
      sum += (now++ - 1) * a[i];
  }
}
