#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int64_t n;
  cin >> n;
  int64_t a[n];
  vector<int64_t> ans = {0};
  cin >> a[0];
  int64_t sum = a[0], total = a[0];
  for (int64_t i = 1; i < n; i++) {
    cin >> a[i];
    if (a[0] >= 2 * a[i]) {
      sum += a[i];
      ans.push_back(i);
    }
    total += a[i];
  }
  if (2 * sum > total) {
    cout << ans.size() << endl;
    for (auto it : ans) {
      cout << it + 1 << ' ';
    }
  } else {
    cout << 0 << endl;
  }
  return 0;
}
