#include <bits/stdc++.h>
using namespace std;
int k, n, sum, ar, i;
int main() {
  cin >> n;
  int a[n], c[n];
  for (i = 0; i < n; i++) {
    cin >> a[i];
    sum = sum + a[i];
  }
  for (i = 0; i < n; i++) {
    sum = sum - a[i];
    if (a[i] * (n - 1) == sum) {
      c[k] = i + 1;
      k++;
    }
    sum = sum + a[i];
  }
  cout << k << endl;
  for (i = 0; i < k; i++) {
    cout << c[i] << " ";
  }
}
