#include <bits/stdc++.h>
using namespace std;
int main() {
  long c = -1, n, s = 0;
  cin >> n;
  int arr[n], res[n];
  for (int i = 0; i < n; i++) arr[i] = res[i] = 0;
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x;
    arr[i] = x;
    s += x;
  }
  for (int i = 0; i < n; i++)
    if ((double)(s - arr[i]) / (double)(n - 1) == (double)arr[i])
      res[++c] = i + 1;
  cout << c + 1 << endl;
  for (int i = 0; i < c + 1; i++) cout << res[i] << " ";
  return 0;
}
