#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n;
  cin >> n;
  long long int arr[n];
  long long int sum = 0;
  for (long long int i = 0; i < n; i++) {
    cin >> arr[i];
    sum += arr[i];
  }
  long long int cnt = 0;
  vector<long long int> v;
  for (long long int i = 0; i < n; i++) {
    sum = sum - arr[i];
    if (sum / (n - 1) == arr[i] && sum % (n - 1) == 0) {
      cnt++;
      v.push_back(i + 1);
    }
    sum = sum + arr[i];
  }
  sort(v.begin(), v.end());
  if (cnt == 0)
    cout << 0;
  else {
    cout << cnt << endl;
    for (long long int i = 0; i < v.size(); i++) cout << v[i] << " ";
  }
  cout << endl;
}
