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