#include <bits/stdc++.h>
const long long mod = 1000000007;
const long long Inf = 2 * 1e9;
using namespace std;
int toint(string s) {
  long long ans = 0;
  for (int(i) = 0; (i) < s.length(); (i)++) ans = ans * 10 + (s[i] - '0');
  return ans;
}
vector<int> a;
vector<pair<int, int>> pr;
int main() {
  ios::sync_with_stdio(false);
  int n, k;
  cin >> n >> k;
  a.resize(n);
  for (int(i) = 0; (i) < n; (i)++) cin >> a[i];
  long long r = 0, ch = 0, count = 0, nn = n;
  for (int(i) = 2; (i) < n; (i)++) {
    r = ch - (i - 1 - count) * (n - i) * a[i - 1];
    ch += (i - 1 - count) * a[i - 1];
    if (r < k) {
      cout << i << endl;
      ch -= (i - 1 - count) * a[i - 1];
      count++;
    }
  }
  return 0;
}
