#include <bits/stdc++.h>
using namespace std;
const int INF = 1.01e9;
int main() {
  int n;
  while (scanf("%d", &n) == 1) {
    vector<int> a(n);
    for (int i = 0; i < n; i++) scanf("%d", &a[i]);
    int sum = 0;
    int sumA = 0;
    vector<int> ans;
    for (int i = 0; i < n; i++) {
      if (i == 0 || a[i] * 2 <= a[0]) {
        sumA += a[i];
        ans.push_back(i);
      }
      sum += a[i];
    }
    if (sumA * 2 > sum) {
      cout << ans.size() << endl;
      for (int x : ans) cout << x + 1 << " ";
      cout << endl;
    } else {
      cout << 0 << endl;
    }
  }
}
