#include <bits/stdc++.h>
using namespace std;
int n;
int a[200001];
int b[200001];
int main() {
  cin >> n;
  int tong = 0;
  int i;
  for (i = 1; i <= n; i++) cin >> a[i], tong += a[i];
  int k = 1;
  i = 1;
  bool ok = true;
  while (i <= n) {
    if (tong % n == 0 && a[i] == tong / n) {
      b[k] = i;
      k++;
      ok = false;
    }
    i++;
  };
  if (ok) {
    cout << 0 << endl;
    return 0;
  }
  cout << k - 1 << endl;
  for (i = 1; i < k; i++) cout << b[i] << " ";
  return 0;
}
