#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int *arr = new int[n];
  double sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> arr[i];
    sum = sum + arr[i];
  }
  sum = sum / n;
  int count = 0;
  for (int j = 0; j < n; j++) {
    if (arr[j] == sum) {
      arr[count] = j + 1;
      count = count + 1;
    }
  }
  if (count == 0)
    cout << count << endl;
  else {
    cout << count << endl;
    for (int i = 0; i < count; i++) {
      cout << arr[i] << " ";
    }
  }
  cin >> n;
  return 0;
}
