#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
const int N = int(3e5) + 99;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long n;
  cin >> n;
  long long res = 0, sum = 0;
  long long v[n + 1];
  vector<long long> ans;
  for (long long i = 1; i <= n; i++) {
    cin >> v[i];
    sum += v[i];
  }
  for (long long i = 1; i <= n; i++) {
    if (i == 1 or v[i] * 2 <= v[1]) {
      res += v[i];
      ans.push_back(i);
    }
  }
  if (res * 2 > sum) {
    cout << ans.size() << "\n";
    for (auto &x : ans) {
      cout << x << " ";
    }
    cout << "\n";
  } else {
    cout << 0 << "\n";
  }
  return 0;
}
