#include <bits/stdc++.h>
using namespace std;
int n, a[1000000], sum;
vector<int> ans;
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]), sum += a[i];
  for (int i = 0; i < n; i++)
    if ((long double)a[i] == (sum - a[i]) / (long double)(n - 1))
      ans.push_back(i + 1);
  printf("%d\n", ans.size());
  for (int i = 0; i < ans.size(); i++) printf("%d ", ans[i]);
  return 0;
}
