#include <bits/stdc++.h>
using namespace std;
long long n, k, A[1000100], A2[1000010], N;
int main() {
  cin >> n >> k;
  for (int i = 1; i <= n; i++) {
    cin >> A[i];
  }
  N = n;
  long long cumsum = 0;
  for (int i = 2, rank = 2; i <= n; i++) {
    long long cumsum2 = cumsum + (rank - 2) * A2[rank - 1];
    long long d = cumsum2 - (rank - 1) * (N - rank) * A[i];
    if (d < k) {
      cout << i << endl;
      N--;
    } else {
      A2[rank] = A[i];
      rank++;
      cumsum = cumsum2;
    }
  }
  return 0;
}
