#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL);
  int n;
  cin >> n;
  int arr[n + 1];
  arr[0] = 0;
  for (int i = 1; i <= n; i++) cin >> arr[i];
  vector<int> x;
  x.push_back(arr[1]);
  for (int i = 2; i <= n; i++) x.push_back(arr[i] - arr[i - 1]);
  vector<int> ans;
  for (int k = 1; k <= n; k++) {
    bool ch = true;
    for (int i = 1; i <= n; i++) {
      if (arr[i] - arr[i - 1] != x[(i - 1) % k]) ch = false;
    }
    if (ch) ans.push_back(k);
  }
  cout << ans.size() << endl;
  for (int i = 0; i < ans.size(); i++) cout << ans[i] << " ";
  return 0;
}
