#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, s = 0;
  cin >> n;
  long long int a[n];
  for (long long int i = 0; i < n; i++) {
    cin >> a[i];
    s += a[i];
  }
  if (s % n != 0) {
    cout << 0 << endl << endl;
    return 0;
  }
  long long int t = s / n;
  vector<long long int> ans;
  for (long long int i = 0; i < n; i++) {
    if (a[i] == t) ans.push_back(i + 1);
  }
  cout << ans.size() << endl;
  for (auto i : ans) {
    cout << i << " ";
  }
}
