#include <bits/stdc++.h>
const int N = 200000 + 10;
int a[N], n, K;
int main() {
  scanf("%d%d", &n, &K);
  for (int i = 0; i < n; ++i) scanf("%d", &a[i]);
  long long pre = 0;
  int tot = n - 1, id = 0;
  for (int i = 0; i < n; ++i) {
    long long d = pre - (long long)a[i] * (tot - id) * id;
    if (d < K) {
      printf("%d\n", i + 1);
      --tot;
    } else {
      pre = pre + (long long)a[i] * id;
      ++id;
    }
  }
  return 0;
}
