#include <bits/stdc++.h>
using namespace std;
int main() {
  int long long n, i, k = 0;
  cin >> n;
  double a[n + 5], s = 0, b[n + 5];
  for (i = 0; i < n; i++) {
    cin >> a[i];
    s += a[i];
  }
  for (i = 0; i < n; i++) {
    double r = (s - a[i]) / (n - 1);
    if (r == a[i]) {
      b[k] = i + 1;
      k++;
    }
  }
  cout << k << endl;
  for (i = 0; i < k; i++) {
    cout << b[i] << " ";
  }
  cout << endl;
  return 0;
}
