#include <bits/stdc++.h>
int main() {
  int n, i, k, t, temp, flag;
  int sum;
  int total;
  int a[10000];
  int x[10000];
  scanf("%d", &n);
  total = 0;
  for (i = 1; i <= n; i++) {
    scanf("%d", &a[i]);
    total = total + a[i];
  }
  sum = a[1];
  int target;
  target = total / 2;
  target = target + 1;
  t = 1;
  flag = 0;
  k = 0;
  if (sum >= target) {
    flag = 4;
    printf("1\n");
    printf("1\n");
    goto z;
  }
  k = 1;
  t = 1;
  x[t] = 1;
  t++;
  for (i = 2; i <= n; i++) {
    temp = 2 * a[i];
    if (a[1] >= temp) {
      sum = sum + a[i];
      k++;
      x[t] = i;
      t++;
    }
    if (sum >= target) {
      flag = 1;
      break;
    }
  }
  if (flag == 1) {
    printf("%d\n", k);
    for (i = 1; i < t; i++) {
      printf("%d ", x[i]);
    }
  }
  if (flag == 0) {
    printf("0\n");
  }
z:
  return 0;
}
