#include <bits/stdc++.h>
using namespace std;
int A[200005];
int main() {
  int n, sum = 0;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> A[i];
    sum += A[i];
  }
  vector<int> vi;
  for (int i = 0; i < n; i++) {
    if (A[i] * (n - 1) == (sum - A[i])) {
      vi.push_back(i + 1);
    }
  }
  printf("%d\n", vi.size());
  for (int i = 0; i < vi.size(); i++) {
    printf("%d ", vi[i]);
  }
}
