#include <bits/stdc++.h>
using namespace std;
int main(int argc, char const *argv[]) {
  int n;
  cin >> n;
  int a[n];
  int sum = 0;
  for (int i = 0; i < n; ++i) {
    cin >> a[i];
    sum += a[i];
  }
  if (sum % 2 == 0) {
    sum = sum / 2;
    sum += 1;
  } else {
    sum = (sum + 1) / 2;
  }
  int x = a[0];
  int sum1 = a[0];
  bool check = false;
  vector<int> v;
  v.push_back(1);
  for (int i = 1; i < n; ++i) {
    if (sum1 >= sum) {
      check = true;
      break;
    } else {
      if (a[i] * 2 <= x) {
        sum1 += a[i];
        v.push_back(i + 1);
      }
    }
  }
  if (sum1 >= sum) {
    check = true;
  }
  if (check) {
    cout << v.size() << endl;
    for (int i = 0; i < v.size(); ++i) {
      cout << v[i] << " ";
    }
    cout << endl;
  } else {
    cout << 0 << endl;
  }
  return 0;
}
