#include <bits/stdc++.h>
using namespace std;
int main() {
  long long int n, i, avg = 0, ctr = 0;
  vector<long long int> v;
  cin >> n;
  long long int a[200000 + 5];
  for (i = 1; i <= n; i++) {
    cin >> a[i];
    avg += a[i];
  }
  for (i = 1; i <= n; i++) {
    if (((avg)-a[i]) * 1.0 / (n - 1) == a[i] * 1.0) {
      ctr++;
      v.push_back(i);
    }
  }
  cout << ctr << endl;
  for (i = 0; i < v.size(); i++) cout << v[i] << " ";
  return 0;
}
