#include <bits/stdc++.h>
using namespace std;
int main() {
  int a[1000], b[1000], min;
  int majority, total, n, k, i, t;
  majority = 0;
  total = 0;
  min = 0;
  cin >> n >> a[0];
  k = 1;
  b[0] = 1;
  min = a[0] / 2;
  total = a[0];
  for (i = 1; i < n; i++) {
    cin >> a[i];
    total += a[i];
  }
  majority = total / 2;
  if (a[0] <= majority) {
    for (i = 1; i < n; i++) {
      if (a[i] <= min) {
        a[0] += a[i];
        b[k] = i + 1;
        k++;
      }
    }
  }
  if (a[0] > majority) {
    cout << k << endl;
    for (i = 0; i < k; i++) cout << b[i] << " ";
  } else
    cout << '0';
  cout << endl;
  return 0;
}
