#include <bits/stdc++.h>
using namespace std;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  int t;
  t = 1;
  while (t--) {
    double n;
    cin >> n;
    double a[200001], sum = 0;
    set<double> s;
    for (int i = 0; i < n; i++) {
      cin >> a[i];
      sum += a[i];
    }
    for (int i = 0; i < n; i++) {
      double z = sum - a[i];
      double y = (z / (n - 1));
      if (y == a[i]) s.insert(i + 1);
    }
    cout << s.size() << endl;
    for (auto i : s) cout << i << " ";
    cout << endl;
  }
  return 0;
}
