#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  cin >> n;
  vector<int> v(n);
  long long 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] == v[i] * (n - 1)) {
      ans.push_back(i + 1);
    }
  }
  cout << ans.size() << endl;
  for (auto x : ans) cout << x << " ";
  cout << endl;
}
