#include <bits/stdc++.h>
using namespace std;
int a[200010], n, S, T;
vector<int> A;
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", a + i), S += a[i];
  for (int i = 0; i < n; i++)
    if (S - a[i] == (long long)a[i] * (n - 1)) A.push_back(i + 1);
  printf("%d\n", (int)A.size());
  for (int i = 0; i < (int)A.size(); i++)
    printf("%d%c", A[i], i == (int)A.size() - 1 ? '\n' : ' ');
  return 0;
}
