#include <bits/stdc++.h>
using namespace std;
int n, p;
int sum, mx;
vector<int> ans;
int32_t main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cin >> n;
  for (int i = (1); i <= (n); i++) {
    if (i == 1) {
      cin >> p;
      ans.push_back(1);
      sum += p;
      mx += p;
    } else {
      int x;
      cin >> x;
      mx += x;
      if (x <= p / 2) {
        ans.push_back(i);
        sum += x;
      }
    }
  }
  if (sum <= mx / 2)
    cout << 0;
  else {
    cout << (int)ans.size() << '\n';
    for (int x : ans) cout << x << " ";
  }
  return 0;
}
