#include <bits/stdc++.h>
using namespace std;
int main() {
  unsigned long long n;
  cin >> n;
  unsigned long long s = 0;
  unsigned long long p[n];
  for (unsigned long long i = 0; i < n; i++) {
    cin >> p[i];
    s += p[i];
  }
  unsigned long long t = p[0];
  unsigned long long c = 1;
  vector<unsigned long long> pp;
  pp.push_back(1);
  while (t < (s / 2 + 1) && c < n) {
    if (p[0] >= p[c] * 2) {
      t += p[c];
      pp.push_back(c + 1);
    }
    c++;
  }
  if (t < (s / 2 + 1)) {
    cout << 0;
  } else {
    cout << pp.size() << endl;
    for (auto e : pp) {
      cout << e << " ";
    }
  }
  return 0;
}
