#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<int> V;
  for (int i = 0; i < n; i++) {
    int x1;
    cin >> x1;
    V.push_back(x1);
  }
  int sum = 0;
  for (int i = 0; i < V.size(); i++) sum = sum + V[i];
  int s = sum / 2;
  int sum1 = V[0];
  if (sum1 > s) {
    cout << 1 << endl;
    cout << 1;
    return 0;
  }
  vector<int> ans;
  ans.push_back(1);
  int c = 0;
  for (int i = 1; i < V.size(); i++) {
    if (V[0] >= (2 * V[i])) {
      sum1 = sum1 + V[i];
      ans.push_back(i + 1);
    }
    if (sum1 > s) {
      c = 1;
      break;
    }
  }
  if (c == 1) {
    cout << ans.size() << endl;
    for (int i = 0; i < ans.size(); i++) cout << ans[i] << " ";
    return 0;
  }
  cout << 0;
  return 0;
}
