#include <bits/stdc++.h>
using namespace std;
double n, i, a, b, x, y, o, z, p, q, sum, c;
int main() {
  cin >> n;
  vector<double> v(n);
  for (i = 0; i < n; i++) cin >> v[i];
  vector<double> r;
  sum = accumulate(v.begin(), v.end(), 0);
  for (i = 0; i < n; i++) {
    c = sum - v[i];
    if (c / (n - 1) == v[i]) {
      r.push_back(i + 1);
    }
  }
  cout << r.size() << endl;
  for (i = 0; i < r.size(); i++) cout << r[i] << " ";
}
