#include <bits/stdc++.h>
int main() {
  int n, i, a[105], sum = 0, count = 0, p[105], q;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%d", &a[i]);
    sum = sum + a[i];
  }
  q = a[0];
  if (a[0] > sum / 2) {
    printf("1\n");
    printf("1\n");
  } else {
    for (i = 1; i < n; i++) {
      if (a[0] > sum / 2)
        break;
      else if (count == 0) {
        if (a[i] <= q / 2) {
          count = 2;
          p[0] = 1;
          p[1] = i + 1;
          a[0] = a[0] + a[i];
        }
      } else {
        if (a[i] <= q / 2) {
          p[count] = i + 1;
          a[0] = a[0] + a[i];
          count++;
        }
      }
    }
    if (a[0] < sum / 2 + 1)
      printf("0");
    else {
      printf("%d\n", count);
      for (i = 0; i < count; i++) printf("%d ", p[i]);
    }
  }
  return 0;
}
