#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  if (n == 1) {
    cout << "0";
    return 0;
  }
  vector<int> v(n);
  int sum = 0;
  for (int i = 0; i < n; ++i) {
    cin >> v[i];
    sum += v[i];
  }
  vector<int> ans;
  for (int i = 0; i < n; ++i)
    if (!((sum - v[i]) % (n - 1)) && v[i] == (sum - v[i]) / (n - 1))
      ans.push_back(i + 1);
  cout << ans.size() << endl;
  for (int i = 0; i < (int)ans.size(); ++i) cout << ans[i] << " ";
  return 0;
}
