#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  ;
  long long int t = 1;
  while (t--) {
    long long int n;
    cin >> n;
    vector<long long int> v(n + 1);
    long long int sum = 0;
    for (long long int i = 1; i <= n; i++) {
      cin >> v[i];
      sum += v[i];
    }
    vector<long long int> ans;
    long long int size = n - 1;
    for (long long int i = 1; i <= n; i++) {
      long long int temp_sum;
      if ((sum - v[i]) % size == 0)
        temp_sum = ((sum - v[i]) / size);
      else
        continue;
      if (v[i] == temp_sum) ans.push_back(i);
    }
    cout << ans.size() << "\n";
    for (auto i : ans) cout << i << " ";
  }
  return 0;
}
