#include <bits/stdc++.h>
using namespace std;
int main() {
  register unsigned long long n, sum = 0, temp = 0;
  cin >> n;
  int a[n];
  for (register int i = 0; i < n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  for (register int i = 0; i < n; i++)
    if (a[i] == (long double)(sum - a[i]) / (n - 1)) temp++;
  cout << temp << endl;
  for (register int i = 0; i < n; i++)
    if (a[i] == (long double)(sum - a[i]) / (n - 1)) cout << i + 1 << ' ';
}
