#include <bits/stdc++.h>
long long GCD(long long x, long long y) {
  if (y == 0) return x;
  return GCD(y, x % y);
}
long long LCM(long long x, long long y) { return (x * y) / GCD(x, y); }
long long MPOW(long long a, long long b, long long m) {
  if (b == 0) return 1;
  long long x = MPOW(a, b / 2, m);
  x = (x * x) % m;
  if (b % 2 == 1) x = (x * a) % m;
  return x;
}
long long MINV(long long a, long long m) { return MPOW(a, m - 2, m); }
long long MFACT(long long n, long long m) {
  if (m <= n)
    return 0;
  else if (n == 0)
    return 1;
  else
    return ((MFACT(n - 1, m) * n) % m);
}
inline long long max(long long a, long long b) { return (a > b) ? a : b; }
inline long long min(long long a, long long b) { return (a < b) ? a : b; }
inline void swap(long long &a, long long &b) {
  long long temp = a;
  a = b;
  b = temp;
  return;
}
inline long long max3(long long a, long long b, long long c) {
  return max(a, max(b, c));
}
inline long long min3(long long a, long long b, long long c) {
  return min(a, min(b, c));
}
void fillsv(bool sv[], long long PMAX) {
  memset(sv, true, sizeof(sv));
  sv[0] = sv[1] = false;
  for (long long p = 2; p * p <= PMAX; p++)
    if (sv[p] == true)
      for (long long i = p * p; i <= PMAX; i += p) sv[i] = false;
}
bool check_prime(long long p) {
  if (p == 1) return false;
  for (long long i = 2; i * i <= p; i++)
    if (p % i == 0) return false;
  return true;
}
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  srand(time(NULL));
  long long n, col, sum = 0, maj;
  cin >> n;
  vector<long long> v(n), k;
  for (long long i = 0; i < n; ++i) {
    cin >> v[i];
    sum += v[i];
  }
  col = v[0] / 2;
  maj = v[0];
  k.push_back(1);
  sum = 1 + (sum / 2);
  for (long long i = 1; i < n; ++i) {
    if (v[i] <= col) {
      maj += v[i];
      k.push_back(i + 1);
    }
    if (maj >= sum) break;
  }
  if (maj < sum) k.clear();
  cout << (k).size() << '\n';
  for (auto x = (k).begin(); x != (k).end(); ++x) cout << *x << ' ';
  cout << '\n';
  return 0;
}
