#include <bits/stdc++.h>
using namespace std;
void findParties(int* seats, int N, int total) {
  int majority = total / 2 + 1;
  bool selected[N];
  for (int i = 0; i < N; i++) selected[i] = false;
  int currSum = seats[0];
  selected[0] = true;
  int allowable = seats[0] / 2;
  int numSelected = 0;
  for (int i = 1; i < N; i++) {
    if (seats[i] <= allowable) {
      currSum = currSum + seats[i];
      selected[i] = true;
      numSelected++;
    }
  }
  if (currSum >= majority) {
    cout << (numSelected + 1) << endl;
    for (int i = 0; i < N; i++) {
      if (selected[i] == true) cout << i + 1 << ' ';
    }
    cout << endl;
  } else
    cout << 0 << endl;
}
int main() {
  int N;
  cin >> N;
  int seats[N];
  int total = 0;
  for (int i = 0; i < N; i++) {
    cin >> seats[i];
    total = total + seats[i];
  }
  findParties(seats, N, total);
}
