#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i;
  cin >> n;
  int a[n];
  cin >> a[0];
  int sum = a[0];
  int total = a[0];
  vector<int> ans;
  ans.push_back(1);
  for (i = 1; i < n; i++) {
    cin >> a[i];
    if (a[i] * 2 <= a[0]) {
      sum += a[i];
      ans.push_back(i + 1);
    }
    total += a[i];
  }
  if (sum * 2 > total) {
    cout << ans.size() << endl;
    for (i = 0; i < ans.size(); i++) {
      cout << ans[i] << ' ';
    }
  } else {
    cout << 0;
  }
}
