#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n], sm = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i];
    sm += a[i];
  }
  vector<int> ind, r;
  int need = sm / 2;
  if (a[0] > need) {
    cout << 1 << endl;
    cout << 1;
    return 0;
  }
  for (int i = 1; i < n; i++) {
    if ((2 * a[i]) <= a[0]) {
      ind.push_back(i + 1);
      r.push_back(a[i]);
    }
  }
  bool ok;
  int u = a[0];
  for (auto x : r) {
    u += x;
  }
  if (u > need) {
    ok = true;
  } else {
    ok = false;
  }
  if (ok) {
    cout << ind.size() + 1 << endl;
    cout << 1 << " ";
    for (auto x : ind) {
      cout << x << " ";
    }
  } else {
    cout << 0;
  }
}
