#include <bits/stdc++.h>
using namespace std;
int main() {
  int x, c = 0;
  cin >> x;
  int s[x], r[x];
  double sum = 0, v;
  for (int i = 0; i < x; i++) {
    cin >> s[i];
    sum += s[i];
  }
  for (int i = 0, t = 0; i < x; i++) {
    sum -= s[i];
    v = sum / (x - 1);
    if (s[i] == v) {
      r[t] = i + 1;
      t++;
      c++;
    }
    sum += s[i];
  }
  cout << c << endl;
  for (int i = 0; i < c; i++) cout << r[i] << " ";
}
