#include <bits/stdc++.h>
using namespace std;
int main(void) {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long int n;
  cin >> n;
  long long int a[n];
  vector<pair<long long int, long long int>> ans, possible;
  long long int sum = 0;
  for (long long int i = 0; i < n; i++) {
    cin >> a[i];
    sum += a[i];
    if (i > 0) {
      if (a[0] >= 2 * a[i]) possible.push_back({a[i], i});
    }
  }
  long long int achieve = sum / 2;
  achieve++;
  long long int rn = a[0];
  ans.push_back({a[0], 0});
  for (long long int i = 0; i < possible.size(); i++) {
    if (rn >= achieve) break;
    ans.push_back(possible[i]);
    rn += possible[i].first;
  }
  if (rn < achieve)
    cout << 0;
  else {
    cout << ans.size() << "\n";
    for (long long int i = 0; i < ans.size(); i++)
      cout << ans[i].second + 1 << " ";
  }
}
