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