#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, s = 0;
  cin >> n;
  vector<long long int> v(n), k;
  for (int i = 0; i < n; i++) {
    cin >> v[i];
    s += v[i];
  }
  if (s % n != 0)
    cout << "0\n";
  else {
    long long int p;
    if (s % n == 0) p = s / n;
    for (int i = 0; i < n; i++) {
      if (v[i] == p) k.push_back(i + 1);
    }
    cout << k.size() << endl;
    for (int i = 0; i < k.size(); i++) cout << k[i] << " ";
    cout << endl;
  }
}
