#include <bits/stdc++.h>
using namespace std;
int a[1200000];
bool vis[1200000];
int main() {
  int n;
  cin >> n;
  int t = 0;
  scanf("%d", &a[0]);
  vis[0] = true;
  int sum = a[0], sum1 = a[0];
  for (int i = 1; i < n; i++) {
    scanf("%d", &a[i]);
    if (a[i] <= a[0] / 2) {
      t++;
      sum1 += a[i];
      vis[i] = true;
    }
    sum += a[i];
  }
  if (sum1 > sum / 2) {
    cout << t + 1 << endl;
    for (int i = 0; i < n; i++) {
      if (vis[i]) printf("%d ", i + 1);
    }
  } else
    printf("0\n");
  return 0;
}
