#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, sum = 0, counter = 0;
  scanf("%d", &n);
  int arr[n];
  for (int i = 0; i < n; i++) {
    scanf("%d", &arr[i]);
    sum += arr[i];
  }
  for (int i = 0; i < n; i++) {
    if (arr[i] * (n - 1) == sum - arr[i]) counter++;
  }
  printf("%d\n", counter);
  for (int i = 0; i < n; i++) {
    if (arr[i] * (n - 1) == sum - arr[i]) printf("%d ", i + 1);
  }
  return 0;
}
