#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, K, a, pos, out = 0, i;
  long long sum = 0, d;
  cin >> N >> K;
  cin >> a;
  pos = 2;
  for (i = 2; i <= N; i++) {
    cin >> a;
    d = sum - 1ll * (N - out - pos) * a * (pos - 1);
    if (d < K) {
      cout << i << endl;
      out++;
    } else {
      sum += a * (pos - 1);
      pos++;
    }
  }
  return 0;
}
