#include <bits/stdc++.h>
using namespace std;
int inf = INT_MAX;
long long modulo(long long num, long long MOD = 998244353) {
  return ((num % MOD) + MOD) % MOD;
}
long long power(long long b, long long e, long long MOD = 998244353) {
  long long ans = 1;
  while (e) {
    if (e % 2) ans = (ans * b) % MOD;
    b = (b * b) % MOD;
    e /= 2;
  }
  return ans;
}
long long inv(long long num, long long MOD = 998244353) {
  return power(modulo(num), MOD - 2, MOD);
}
long long gcd(long long a, long long b) {
  return ((b == 0) ? a : gcd(b, a % b));
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  int n;
  cin >> n;
  int arr[n];
  long long sum = 0;
  for (int i = 0; i < n; ++i) {
    cin >> arr[i];
    sum = sum + arr[i];
  }
  int k = 1, flag = 0;
  vector<int> v;
  v.push_back(0);
  long long temp = arr[0];
  if (temp > sum / 2) {
    cout << k << endl;
    for (int i = 0; i < v.size(); ++i) {
      cout << v[i] + 1 << " ";
    }
  } else {
    for (int i = 1; i < n; ++i) {
      if (arr[0] / 2 >= arr[i]) {
        k++;
        temp = temp + arr[i];
        v.push_back(i);
      }
      if (temp > sum / 2) {
        cout << k << endl;
        for (int i = 0; i < v.size(); ++i) {
          cout << v[i] + 1 << " ";
        }
        return 0;
      }
    }
    cout << 0;
  }
  return 0;
}
