#include <bits/stdc++.h>   using namespace std;   const long long N = 1e6 + 10;   int a[N], b[N];   int main() {     int n;     cin >> n;     for (int i = 1; i <= n; i++) {       cin >> a[i];     }     vector<int> ans;     for (int i = 1; i <= n; i++) {       b[i] = a[i] - a[i - 1];     }     for (int i = 1; i <= n; i++) {       int flag = 0;       for (int j = 1; i + j <= n; j++) {         if (b[j] != b[i + j]) {           flag++;           break;         }       }       if (!flag) {         ans.push_back(i);       }     }     cout << ans.size() << endl;     for (auto i : ans) cout << i <<    ;     return 0;   }   