#include <bits/stdc++.h>
using namespace std;
const int maxn = 5e5 + 5;
const int inf = 0x3f3f3f3f;
int n;
int main() {
  cin >> n;
  vector<long long> a(n + 1);
  long long sum = 0;
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int i = 1; i <= n; i++) sum += a[i];
  long long res = a[1];
  for (int i = 1; i <= n; i++) {
    if (a[i] <= a[1] / 2) res += a[i];
  }
  if (res > sum / 2) {
    vector<int> ans;
    for (int i = 1; i <= n; i++) {
      if (i == 1)
        ans.push_back(i);
      else if (a[i] * 2 <= a[1])
        ans.push_back(i);
    }
    cout << ans.size() << "\n";
    for (auto it : ans) cout << it << " ";
  } else {
    cout << 0 << "\n";
  }
  return 0;
}
