#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, total = 0, total1 = 0;
  scanf("%d", &n);
  int num[n];
  for (i = 0; i < n; i++) {
    scanf("%d", &num[i]);
    total = total + num[i];
  }
  int sum = 0;
  if (n == 2) {
    if (num[0] > num[1]) {
      printf("1\n1");
    } else
      printf("0\n");
  } else {
    total1 = num[0];
    for (i = 1; i < n; i++) {
      if (num[i] <= num[0] / 2) {
        sum = sum + 1;
        total1 = total1 + num[i];
      }
    }
    if (sum == 0 || total1 <= total / 2) {
      printf("0\n");
    } else {
      printf("%d\n1 ", sum + 1);
      for (i = 1; i < n; i++) {
        if (num[i] <= num[0] / 2) {
          printf("%d ", i + 1);
        }
      }
    }
  }
}
