#include <bits/stdc++.h>
using namespace std;
int n, t;
double a[200005], sum;
int w[200005];
int main() {
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int i = 1; i <= n; i++) {
    if (sum == 0)
      for (int j = 1; j <= n; j++) sum += a[j];
    if ((sum - a[i]) * 1.0 / (n - 1) == a[i]) {
      t++;
      w[t] = i;
    }
  }
  cout << t << endl;
  for (int i = 1; i <= t; i++) cout << w[i] << " ";
  return 0;
}
