#include <bits/stdc++.h>
using namespace std;
inline int read() {
  char ch = getchar();
  int ret = 0, f = 1;
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  for (; ch >= '0' && ch <= '9'; ch = getchar()) ret = ret * 10 + ch - '0';
  return ret * f;
}
inline void print(string name, int *arr, int len) {
  for (int i = 1; i <= len; ++i) printf("%s[%d]=%d\n", name.c_str(), i, arr[i]);
  puts("");
}
inline void print(string name, int a) {
  printf("%s=%d\n", name.c_str(), a);
  puts("");
}
const int INF = 1 << 30;
const int maxn = 10000 + 10;
int a[maxn];
vector<int> ans;
int main() {
  int n, all = 0;
  cin >> n;
  for (int i = 1; i <= n; ++i) {
    cin >> a[i];
    all += a[i];
  }
  ans.push_back(1);
  int sum = a[1];
  if (sum * 2 > all) {
    printf("1\n1");
    return 0;
  }
  for (int i = 2; i <= n; ++i)
    if (a[i] * 2 <= a[1]) {
      ans.push_back(i);
      if ((sum += a[i]) * 2 > all) {
        cout << ans.size() << endl;
        for (int i = 0; i <= (int)ans.size() - 1; ++i) printf("%d ", ans[i]);
        return 0;
      }
    }
  puts("0");
  return 0;
}
