#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const long long N = 1e6 + 5;
long long power(long long a, long long b) {
  long long ret = 1;
  while (b) {
    if (b & 1) ret *= a;
    a *= a;
    if (ret >= MOD) ret %= MOD;
    if (a >= MOD) a %= MOD;
    b >>= 1;
  }
  return ret;
}
long long invmod(long long x) { return power(x, MOD - 2); }
long long gcd(long long a, long long b) {
  if (a == 0)
    return b;
  else
    return gcd(b % a, a);
}
int32_t main() {
  long long n;
  cin >> n;
  long long a[N];
  long long sum = 0;
  vector<long long> v;
  for (long long i = 1; i <= n; i++) {
    cin >> a[i];
    sum += a[i];
  }
  for (long long i = 1; i <= n; i++) {
    sum -= a[i];
    if (sum % (n - 1) == 0)
      if (sum / (n - 1) == a[i]) v.push_back(i);
    sum += a[i];
  }
  cout << v.size() << endl;
  for (auto it : v) cout << it << " ";
}
