#include <bits/stdc++.h>
using namespace std;
long long power(long long a, long long b) {
  if (b == 0) return 1;
  if (b == 1)
    return a;
  else {
    long long t = power(a, b / 2);
    if (b % 2 == 0)
      return ((t % 1000000007) * (t % 1000000007)) % 1000000007;
    else
      return ((((t % 1000000007) * (t % 1000000007)) % 1000000007) *
              ((a % 1000000007) % 1000000007)) %
             1000000007;
  }
}
void solve() {
  long long n, s = 0, x, i, c = 0;
  vector<long long> v;
  cin >> n;
  long long a[n + 1];
  for (i = 0; i < n; i++) {
    cin >> a[i];
    s += a[i];
  }
  s = s / 2 + 1;
  v.push_back(1);
  x = a[0];
  if (x >= s) {
    cout << "1\n";
    cout << "1";
  } else {
    for (i = 1; i < n; i++) {
      if (a[i] * 2 <= a[0]) {
        x += a[i];
        v.push_back(i + 1);
        if (x >= s) {
          c = 1;
          break;
        }
      }
    }
    if (c == 0)
      cout << "0\n";
    else {
      cout << v.size() << "\n";
      for (auto val : v) cout << val << " ";
    }
  }
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t = 1;
  while (t--) {
    solve();
  }
  return 0;
}
