#include <bits/stdc++.h>
using namespace std;
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
int n;
int seat[100];
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0), cout.tie(0);
  cin >> n;
  for (int i = 0; i < n; i++) cin >> seat[i];
  int sum = 0;
  for (int i = 0; i < n; i++) sum += seat[i];
  vector<int> ans;
  ans.push_back(0);
  int curSum = seat[0];
  for (int i = 1; i < n; i++) {
    if (seat[i] * 2 <= seat[0]) {
      ans.push_back(i);
      curSum += seat[i];
    }
  }
  if (curSum > sum / 2) {
    cout << ans.size() << "\n";
    for (int i = 0; i < ans.size(); i++) cout << ans[i] + 1 << ' ';
  } else
    cout << 0;
}
