#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  while (scanf("%d", &n) == 1) {
    int ara[n + 4], diftab[n + 4];
    ara[0] = 0;
    for (int i = 1; i <= n; i++) {
      scanf("%d", &ara[i]);
      diftab[i - 1] = ara[i] - ara[i - 1];
    }
    int ansara[n + 1], index = 0;
    for (int i = 1; i <= n; i++) {
      bool paisi = true;
      for (int j = 0; j < n; j++) {
        if (diftab[j] != diftab[j % i]) {
          paisi = false;
          break;
        }
      }
      if (paisi) ansara[index++] = i;
    }
    printf("%d\n", index);
    for (int i = 0; index > i; i++) printf("%d ", ansara[i]);
    printf("\n");
  }
}
