#include <bits/stdc++.h>
using namespace std;
mt19937_64 rnd(time(0));
const long long inf = 1e18 + 7;
void solve() {
  int n;
  cin >> n;
  int a[n];
  long long sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  vector<int> ans;
  ans.push_back(0);
  long long sum_now = a[0];
  for (int i = 1; i < n; i++) {
    if (a[i] * 2 <= a[0]) {
      ans.push_back(i);
      sum_now += a[i];
    }
  }
  if (sum / 2 >= sum_now) {
    cout << 0;
  } else {
    cout << ans.size() << endl;
    for (int i = 0; i < ans.size(); i++) cout << ans[i] + 1 << ' ';
  }
}
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  ;
  long long q = 1;
  while (q--) {
    solve();
  }
  return 0;
}
