#include <bits/stdc++.h>
using namespace std;
void read(int &x) {
  x = 0;
  int f = 1;
  char ch = getchar();
  for (; !isdigit(ch); ch = getchar())
    if (ch == '-') f = -f;
  for (; isdigit(ch); ch = getchar()) x = x * 10 + ch - '0';
  x *= f;
}
void print(int x) {
  if (x < 0) putchar('-'), x = -x;
  if (!x) return;
  print(x / 10), putchar(x % 10 + 48);
}
void write(int x) {
  if (!x)
    putchar('0');
  else
    print(x);
  putchar('\n');
}
const int maxn = 1e6 + 10;
const int inf = 1e9;
const double eps = 1e-8;
const int mod = 1e9 + 7;
int n, a[maxn], s, t, cnt = 1;
int main() {
  read(n);
  for (int i = 1; i <= n; i++) read(a[i]), s += a[i];
  t += a[1];
  for (int i = 2; i <= n; i++)
    if (a[1] >= a[i] * 2) t += a[i], cnt++;
  if (t <= s / 2) return puts("0"), 0;
  write(cnt);
  printf("1 ");
  for (int i = 2; i <= n; i++)
    if (a[1] >= a[i] * 2) printf("%d ", i);
  puts("");
  return 0;
}
