#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  int n, s = 0, s1 = 0;
  cin >> n;
  vector<int> aa(n);
  vector<int> bb;
  for (int i = 0; i < n; i++) {
    cin >> aa[i];
    s += aa[i];
  }
  if (aa[0] > s / 2) {
    cout << 1 << endl;
    cout << 1 << endl;
  } else {
    bb.push_back(1);
    s1 += aa[0];
    for (int i = 1; i < n; i++) {
      if (aa[0] / 2 >= aa[i]) {
        bb.push_back(i + 1);
        s1 += aa[i];
      }
      if (s1 > s / 2) {
        break;
      }
    }
    if (bb.size() == 1) {
      cout << 0 << endl;
    } else {
      if (s1 > s / 2) {
        cout << bb.size() << endl;
        for (int i = 0; i < bb.size(); i++) {
          cout << bb[i] << " ";
        }
        cout << endl;
      } else {
        cout << 0 << endl;
      }
    }
  }
}
