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