#include <bits/stdc++.h>
using namespace std;
int n, sum = 0;
int a[200006];
int main() {
  cin >> n;
  for (int i = 1; i <= (n); i++) cin >> a[i];
  for (int i = 1; i <= (n); i++) sum += a[i];
  int cnt = 0;
  for (int i = 1; i <= (n); i++)
    if (a[i] * (n - 1) == sum - a[i]) cnt++;
  cout << cnt << endl;
  if (!cnt) return 0;
  for (int i = 1; i <= (n); i++)
    if (a[i] * (n - 1) == sum - a[i]) cout << i << " ";
  return 0;
}
